WO2024208330A1

WO2024208330A1 - Communication method and apparatus

Info

Publication number: WO2024208330A1
Application number: PCT/CN2024/086067
Authority: WO
Inventors: 董昶钊; 高翔; 张哲宁; 刘显达; 刘鹍鹏
Original assignee: 华为技术有限公司
Priority date: 2023-04-07
Filing date: 2024-04-03
Publication date: 2024-10-10
Also published as: CN118784184A

Abstract

The present application relates to the technical field of communications. Provided are a communication method and apparatus, which are used for solving the problem of an existing port indication being inapplicable when the number of antenna ports increases. The method comprises: receiving first indication information, which is used for indicating a first port combination, wherein the first port combination comprises a number i of antenna ports, the first port combination is one port combination in a first port combination sub-set, the first port combination sub-set is one sub-set in a port combination set, the first port combination sub-set comprises a number N of antenna port combinations, and the port combination set comprises a number M of antenna port combinations, i, N and M all being positive integers and N being less than M; and sending or receiving a demodulation reference signal (DMRS) according to the antenna ports comprised in the first port combination.

Description

A communication method and device

This application claims the priority of the Chinese patent application filed with the State Intellectual Property Office on April 7, 2023, with application number 202310411249.0 and application name “A Communication Method and Device”, all contents of which are incorporated by reference in this application.

Technical Field

The present application relates to the field of communication technology, and in particular to a communication method and device.

Background Art

In the communication system, the demodulation reference signal (DMRS) is used by the receiving end to estimate the equivalent channel matrix experienced by the data channel (such as the physical downlink shared channel or the physical uplink shared channel) or the control channel (such as the physical downlink control channel), so as to detect and demodulate the data. Taking the physical downlink shared channel (PDSCH) as an example, DMRS uses the same precoding matrix as PDSCH to ensure that DMRS and PDSCH experience the same equivalent channel. When the network device receives DMRS and PDSCH, it can perform equivalent channel estimation based on DMRS and then demodulate the data carried in PDSCH.

At present, the protocol defines the DMRS symbols and time-frequency resource mapping methods corresponding to the DMRS port number. When scheduling data, the network equipment can indicate the corresponding DMRS port to the terminal, including the DMRS port number and the DMRS port number. In order to ensure the quality of channel estimation, different DMRS ports are usually orthogonal ports, and the DMRS symbols corresponding to different DMRS ports are orthogonal in the frequency domain, time-frequency or code domain. Based on the allocated DMRS port, the terminal performs corresponding data transmission in accordance with the DMRS signal generation method and time-frequency resource mapping rules defined in the protocol. The current DMRS port indication method may include semi-statically configuring the DMRS type and number of symbols through high-level signaling, and dynamically notifying the allocated DMRS port index through downlink control information (Downlink Control Information, DCI).

In the existing related technologies, the system supports a maximum of 12 orthogonal DMRS ports. However, with the increase in the number of terminals and the increase in the number of transmission streams in the communication scenarios, 12 DMRS ports may not be able to meet the requirements of the communication system for the number of transmission layers. The orthogonal DMRS ports can be increased by increasing the time domain unit occupied by DMRS, increasing the degree of frequency division multiplexing, or increasing the degree of code division multiplexing. For example, the total number of DMRS ports multiplexed in the same time-frequency resources can be expanded to a maximum of 24 through code division multiplexing enhancement technology. Based on this, the current DMRS port indication method is no longer applicable, and a new DMRS port indication method needs to be designed.

Summary of the invention

The present application provides a communication method and device for solving the problem that the existing port indication is no longer applicable after the number of antenna ports is expanded.

In order to achieve the above purpose, this application adopts the following technical solutions:

In a first aspect, a communication method is provided, the method comprising: receiving first indication information, the first indication information being used to indicate a first port combination, wherein the first port combination includes i antenna ports, the first port combination is a port combination in a first port combination subset, the first port combination subset is a subset in a port combination set, the first port combination subset includes N antenna port combinations, the port combination set includes M antenna port combinations, i, N and M are all positive integers and N is less than M; the first port combination subset also includes a second port combination, the second port combination includes j antenna ports, j is a positive integer and i is not equal to j; the number of preamble symbols corresponding to the first port combination subset is the same as the number of preamble symbols corresponding to the port combination set; and a demodulation reference signal DMRS is sent or received according to the antenna ports included in the first port combination.

In the above implementation mode, when the number of antenna ports is expanded, the number of antenna port combinations increases accordingly. The network device can configure some port combinations in the port combination set for the terminal, that is, the first port combination subset, and indicate one of the port combinations in the first port combination subset through the first indication information, such as the first port combination, thereby reducing the number of port combinations configured for the terminal to reduce the signaling overhead of the indication information and realize multi-user port scheduling as much as possible.

In one embodiment, different numbers of antenna ports corresponding to N antenna port combinations in the first port combination subset constitute a first port number set, different numbers of antenna ports corresponding to M antenna port combinations in the port combination set constitute a second port number set, and the first port number set is a subset of the second port number set, wherein each antenna port combination corresponds to an antenna port number.

In the above implementation mode, each port combination corresponds to a port number value, the port number value set corresponding to the N port combinations included in the first port combination subset is the first port number set, and the port number value set corresponding to the M port combinations included in the port combination set is The value set is a second port number set, and the first port number set is a subset of the second port number set.

In one implementation, the first port number set is equal to the second port number set. Further, the port number value corresponding to any port combination subset is the same as the full set, so that the total number of ports supported by the antenna port combination of the full set of port combinations can be satisfied, so that the network device can configure the port subset for the terminal to meet the number of transmission streams supported by the full set of port combinations without affecting the transmission efficiency.

In one embodiment, the method further includes: receiving second indication information, where the second indication information is used to indicate the DMRS configuration type and the maximum length of the preamble symbol of the port combination set and/or the first port combination subset.

In the above-mentioned implementation mode, the network device can send a second indication information to the terminal to indicate the configured port combination subset and/or the full set of port combinations for the terminal. The second indication information can carry the antenna port configuration type and the maximum length of the prefix symbol, so that the terminal can determine the configured port combination subset and/or the full set of port combinations based on the antenna port configuration type and the maximum length of the prefix symbol.

In one embodiment, the method further includes: receiving third indication information, where the third indication information is used to indicate the number of code division multiplexing CDM groups that do not transmit data.

In one implementation, the first indication information is further used to indicate the number of CDM groups not transmitting data corresponding to the first port combination.

In one embodiment, the second indication information and/or the third indication information is carried in the radio resource control RRC signaling, or carried in the medium access control control unit MAC CE.

In one implementation, the second indication information and the third indication information are carried in the first RRC signaling, or carried in the first MAC CE. The second indication information and the third indication information can be carried in one RRC signaling or MAC CE at the same time, thereby saving signaling overhead.

In one implementation, the first indication information includes index information of the first port combination in the first port combination subset. The first indication information may carry an index value of the first port combination in the first port combination subset. Since the first port combination subset is a part of the port combination full set, the number of port combinations is relatively small compared to the full set. Therefore, the indication bits occupied by the index value used to indicate one of the port combinations are also relatively small compared to the full set, which can reduce the signaling overhead of the indication.

In one implementation, if the antenna port configuration type of the first port combination subset is type one, the number of ports corresponding to the N antenna port combinations included in the first port combination subset includes 1-8.

In one embodiment, the number of CDM groups that do not transmit data corresponding to the N antenna port combinations in the first port combination subset is a first CDM group number set, and the number of CDM groups that do not transmit data corresponding to the M antenna port combinations in the port combination set is a second CDM group number set, and the second CDM group number set includes the first CDM group number set.

In the above implementation, the number of CDM groups that do not transmit data can be used as a basis for dividing the port combination subsets, that is, the port combinations with the same number of CDM groups that do not transmit data in the port combination set can be divided into the same port combination subset. For example, if the number of CDM groups that do not transmit data in the M port combinations in the port combination set is 1 or 2, then the first port combination subset may only include multiple port combinations with 1 CDM group that does not transmit data, or the first port combination subset may only include multiple port combinations with 2 CDM groups that do not transmit data, or the first port combination subset may only include multiple port combinations with 1 CDM group that does not transmit data and 2 CDM groups that do not transmit data.

In one implementation, the first CDM group number set is equal to the second CDM group number set.

Exemplarily, taking the antenna port configuration type as type 1 and the maximum length of the preamble symbol as 1 as an example, the existing protocol includes ports 0 and 1, the extended DMRS ports include ports 8 and 9, and the port combination set may include as shown in the following table. Then, multiple port combinations in which the number of CDM groups that do not transmit data is 1 may be divided into a first port combination subset, as shown in the following table.

Port combination set

First port combination subset

Further, a plurality of port combinations in which the number of CDM groups not transmitting data is 2 may be divided into a second port combination subset, as shown in the following table.

Second Port Combination Subset

It can be seen that the number of index values in the port combination subset is smaller than the number of index values in the port combination full set, and therefore, the indication overhead required for the first indication information is smaller.

In one embodiment, the first port combination subset also includes B port combinations, and all antenna port numbers corresponding to any one of the B port combinations are associated with all antenna port numbers corresponding to at least one port in the B port combinations in the port combination set and a first bias, wherein the first bias indicates an offset value of the antenna port number, and B is a positive integer and B is less than or equal to N.

In one embodiment, the B port combinations in the first port combination subset correspond to the B port combinations in the port combination set; wherein the B port combinations in the first port combination subset include port combinations indexed as {1, 2, 3, ...B}, wherein the port number contained in the port combination corresponding to each port combination index is associated with the port number contained in the port combination with the same index in the B port combinations in the port combination set and the first bias.

In one embodiment, the port combination set also includes a second port combination subset, the second port combination subset includes B antenna port combinations, the second port combination subset also includes B port combinations, all antenna port numbers corresponding to any one of the B port combinations are associated with all antenna port numbers corresponding to at least one port in the B port combinations in the first port combination subset and a first bias; wherein the B port combinations in the second port combination subset correspond one-to-one to the B port combinations in the first port combination subset; wherein the B port combinations in the second port combination subset include port combinations indexed as {1, 2, 3, ...B}, wherein the port number contained in the port combination corresponding to each port combination index is associated with the port number contained in the port combination with the same index in the B port combinations in the first port combination subset and a first bias.

Exemplarily, taking the antenna port configuration type as type 1 and the maximum length of the preamble symbol as 1 as an example, B can be 9, that is, the first port combination subset can include the following 9 port combinations corresponding to index values 0 to 8, which can be obtained according to all antenna port numbers corresponding to any port in the B port combinations in the port combination set and the first offset. The B port combinations in the first/second port combination subset can be shown in the following table:

In one implementation, the association includes an addition operation, and if the DMRS configuration type of the first port combination subset is type one or enhanced type one, the first offset is 8 or -8.

In one implementation, the associating includes an addition operation, and if the DMRS configuration type of the first port combination subset is type 2 or enhanced type 2, the first offset is 12 or -12.

In one implementation, the port combination set further includes A antenna port combinations, the number of antenna ports corresponding to any one of the A antenna port combinations is 3 or 4, and A is a positive integer and is less than or equal to M.

In one implementation, the first port combination subset further includes C antenna port combinations, and the number of antenna ports corresponding to any one of the C antenna port combinations is 3 or 4.

In one implementation, multiple antenna ports corresponding to any antenna port combination among the C antenna port combinations in the first port combination subset are in the same CDM group, where C is a positive integer and C is less than or equal to N.

Exemplarily, taking the antenna port configuration type as type 1 and the maximum length of the preamble symbol as 1 as an example, C can be 6, that is, the first port combination subset can include the following 6 port combinations, [0,1,8], [0,1,8,9], [0,1,8], [0,1,8,9], [2,3,10], [2,3,10,11]. Among them, ports 0,1,8,9 are in the same CDM group, and ports 2,3,10,11 are in the same CDM group.

In one embodiment, the port combination set also includes a second port combination subset, the second port combination subset also includes C antenna port combinations, the number of antenna ports corresponding to any one of the C antenna port combinations is 3 or 4, and the C antenna port combinations included in the first port combination subset are the same as the C antenna port combinations included in the second port combination subset.

In one implementation, the A antenna port combinations include the C antenna port combinations.

In one implementation, multiple antenna ports corresponding to at least one antenna port combination among the A antenna port combinations included in the port combination set are in different CDM groups; and the at least one antenna port combination does not belong to the C antenna port combinations.

In one implementation, at least one antenna port combination except the C antenna port combinations among the A antenna port combinations in the port combination set is used for single-user transmission, or no other antenna ports are scheduled simultaneously.

In one implementation, the first port combination subset or the second port combination subset includes D antenna port combinations, and the number of antenna ports corresponding to any port combination of the D antenna port combinations is 5 to 8.

In one implementation, the first indication information is carried in downlink control information DCI.

In one implementation, if the DCI also includes a transmission configuration indication TCI field, all code points in the TCI field are mapped to one TCI state.

In a second aspect, a communication method is provided, the method comprising: sending first indication information, the first indication information being used to indicate a first port combination, wherein the first port combination includes i antenna ports, the first port combination is a port combination in a first port combination subset, the first port combination subset is a subset in a port combination set, the first port combination subset includes N antenna port combinations, the port combination set includes M antenna port combinations, i, N and M are all positive integers and N is less than M; the first port combination subset also includes a second port combination, the second port combination includes j antenna ports, j is a positive integer and i and j are not equal; the number of preamble symbols corresponding to the first port combination subset is the same as the number of preamble symbols corresponding to the port combination set; and a demodulation reference signal DMRS is sent or received according to the antenna ports included in the first port combination.

In one implementation, the first port number set is equal to the second port number set.

In one implementation, the method further includes: sending second indication information, where the second indication information is used to indicate the DMRS configuration type and the maximum length of the preamble symbol of the port combination set and/or the first port combination subset.

In one embodiment, the method further includes: sending third indication information, where the third indication information is used to indicate the number of code division multiplexing CDM groups that do not transmit data.

In one embodiment, the second indication information and the third indication information are carried in the first RRC signaling, or, are carried in the first MAC CE.

In one implementation, the first indication information includes index information of the first port combination in the first port combination subset.

In one embodiment, the port combination set also includes a second port combination subset, the second port combination subset also includes B port combinations, all antenna port numbers corresponding to any one of the B port combinations are associated with all antenna port numbers corresponding to at least one port in the B port combinations in the first port combination subset and a first bias; wherein the B port combinations in the second port combination subset correspond one-to-one to the B port combinations in the first port combination subset; wherein the B port combinations in the second port combination subset include port combinations indexed as {1, 2, 3, ...B}, wherein the port number contained in the port combination corresponding to each port combination index is associated with the port number contained in the port combination with the same index in the B port combinations in the first port combination subset and a first bias.

In one implementation, the associating may include an addition operation, and if the DMRS configuration type of the first port combination subset port is type one or enhanced type one, the first offset is 8 or -8.

In one implementation, the associating may include an addition operation, and if the DMRS configuration type of the first port combination subset is type 2 or enhanced type 2, the first offset is 12 or -12.

In one implementation, the port combination set further includes A antenna port combinations, the number of antenna ports corresponding to any port combination pair of the A antenna port combinations is 3 or 4, and A is a positive integer and A is less than or equal to M.

In one implementation, the first port combination subset further includes C antenna port combinations, and the number of antenna ports corresponding to any port combination pair of the C antenna port combinations is 3 or 4.

In one embodiment, the port combination set also includes a second port combination subset, the second port combination subset also includes C antenna port combinations, the number of antenna ports corresponding to any port combination pair of the C antenna port combinations is 3 or 4, and the C antenna port combinations included in the first port combination subset are the same as the C antenna port combinations included in the second port combination subset.

In one implementation, multiple antenna ports corresponding to at least one antenna port combination among the A antenna port combinations included in the port combination set are in different CDM groups; and at least one antenna port combination does not belong to the C antenna port combinations.

In one implementation, the first port combination subset or the second port combination subset includes D antenna port combinations, and the number of antenna ports corresponding to any port combination pair of the D antenna port combinations is 5 to 8.

In a third aspect, a communication device is provided, which includes a transceiver module, which is used to send or receive signals or data, and may also include a processing module, which is used to implement steps other than sending or receiving, and the communication device is used to execute any method as described in any one of the first aspects above.

In a fourth aspect, a communication device is provided, which includes a transceiver module, which is used to send or receive signals or data, and may also include a processing module, which is used to implement steps other than sending or receiving. The communication device is used to execute any method as described in the second aspect above.

In a fifth aspect, a communication device is provided. The device includes a processor, the processor is coupled to a memory; the memory The device is used to store computer programs or instructions; the processor is used to execute the computer programs or instructions stored in the memory, so that the device performs the method as described in any one of the first aspects above.

In a sixth aspect, a communication device is provided. The device includes a processor, the processor is coupled to a memory, the memory is used to store a computer program or instruction, and the processor is used to execute the computer program or instruction stored in the memory, so that the device performs any method as described in any one of the second aspects above.

In a seventh aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are called by the computer, the computer is used to cause the computer to execute any one of the methods described in the first aspect.

In an eighth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are called by the computer, the computer is used to cause the computer to execute any one of the methods in the second aspect.

According to a ninth aspect, a computer program product comprising instructions is provided, and when the computer program product is run on a computer, the computer is caused to execute the method described in any one of the above-mentioned first aspects.

In a tenth aspect, a computer program product comprising instructions is provided, and when the computer program product is run on a computer, the computer is caused to execute the method described in any one of the above-mentioned second aspects.

In an eleventh aspect, a chip is provided. The chip is located in a relay device, the chip includes a processor and a memory coupled to the processor, the memory stores a computer program code, and the computer program code includes instructions. When the instructions are executed by the processor, the relay device performs the method as described in any one of the above-mentioned first aspects.

In a twelfth aspect, a chip is provided. The chip is located in a network device, the chip includes a processor and a memory coupled to the processor, the memory stores a computer program code, and the computer program code includes instructions. When the instructions are executed by the processor, the network device performs the method as described in any one of the above second aspects.

In a thirteenth aspect, a communication system is provided, comprising a communication device as described in any one of the third aspect and a communication device as described in any one of the fourth aspect.

It can be understood that any of the relay communication methods, communication devices, communication systems, computer program products, computer-readable storage media or chips, etc. provided above can be implemented by the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the first aspect above and will not be repeated here.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a time-frequency resource;

FIG2 is a schematic diagram of the time-frequency resource mapping of Type 1 DMRS for a single symbol;

FIG3 is a schematic diagram of dual-symbol Type 1 DMRS time-frequency resource mapping;

FIG4 is a schematic diagram of the time-frequency resource mapping of Type 2 DMRS for a single symbol;

FIG5A is a schematic diagram of dual-symbol Type 2 DMRS time-frequency resource mapping;

FIG5B is a schematic diagram of port configuration after DMRS port expansion according to an embodiment of the present application;

FIG6 is a schematic diagram of a communication system architecture provided in an embodiment of the present application;

FIG7 is a schematic diagram of the hardware structure of a communication device provided in an embodiment of the present application;

FIG8 is a flow chart of a communication method provided in an embodiment of the present application;

FIG. 9 is a schematic diagram of the structure of a communication device provided in an embodiment of the present application.

DETAILED DESCRIPTION

In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this embodiment, unless otherwise specified, "plurality" means two or more.

It should be noted that, in this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in this application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. For example, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection of this application.

First, the implementation environment and application scenarios of the embodiments of the present application are briefly introduced.

1. Resource block (RB)

In wireless resources, the smallest resource granularity in the time domain can be an orthogonal frequency division multiplexing (OFDM) symbol, which can be referred to as a symbol. In the frequency domain, the smallest resource granularity can be a subcarrier. An OFDM symbol and a subcarrier can form a resource element (RE), and a time slot and 12 consecutive subcarriers in the frequency domain can form an RB. Among them, a time slot can include multiple consecutive OFDM symbols in the time domain, for example, a time slot includes 12 consecutive OFDM symbols or 14 consecutive OFDM symbols, etc.

As shown in Figure 1, it is a schematic diagram of a time-frequency resource. In Figure 1, when the physical layer performs resource mapping, RE is used as the basic unit, RB is the basic scheduling unit in the frequency domain for data channel allocation, and one RB includes 12 consecutive subcarriers in the frequency domain and 14 consecutive OFDM symbols in the time domain.

It can be understood that FIG. 1 is only a schematic diagram of an RB, and in a specific application, an RB may include more or fewer subcarriers than those shown in FIG. 1 , without limitation.

In addition, the embodiment of the present application does not limit the frequency interval (i.e., subcarrier spacing) between adjacent subcarriers. For example, in the embodiment of the present application, the subcarrier spacing may be 15KHz, 30KHz, 60KHz, 120KHz, or 240KHz, etc. Different subcarrier spacings may correspond to different OFDM symbol lengths.

2. Spatial layer

For a spatial multiplexing multiple input multiple output (MIMO) system, multiple parallel data streams can be transmitted simultaneously on the same time-frequency resources. Each data stream is called a spatial layer or transport layer or spatial stream or transport stream or stream.

3. Orthogonal cover code (OCC)

Any two sequences are orthogonal sequence groups. OCC is used in a code division multiplexing (CDM) group to ensure the orthogonality of the ports, thereby reducing the interference of the reference signal (RS) transmitted between the ports. For example, taking a CDM group occupying 4 REs as an example, the CDM group provides 4 orthogonal ports, and these 4 orthogonal ports use 4 OCCs to ensure the orthogonality of the ports. For example, the OCC of the first port is [1,1,1,1], the OCC of the second port is [1,-1,1,-1], the OCC of the third port is [1,1,-1,-1], and the OCC of the fourth port is [1,-1,-1,1].

4. Antenna port

In the embodiment of the present application, an antenna port can be understood as a transmitting antenna identified by the receiving end, or a transmitting antenna that can be distinguished in space. An antenna port can be defined based on a reference signal associated with the antenna port. An antenna port can be a physical antenna on a transmitting device, or a weighted combination of multiple physical antennas on a transmitting device. In the embodiment of the present application, unless otherwise specified, one antenna port corresponds to one reference signal.

The antenna port is used to carry at least one of a specific physical channel and a physical signal. Taking the DMRS port as an example, the DMRS port is the antenna port that carries the DMRS. The signals sent through the same antenna port, regardless of whether these signals are sent through the same or different physical antennas, the channels corresponding to the paths experienced by these signals in spatial transmission can be considered to be the same or related. In other words, the signals sent from the same antenna port can be considered to have the same or related channels when demodulated by the receiving end. In other words, the antenna port defines the channel on a certain symbol. If the antenna ports of two symbols are the same, the channel on one symbol can be inferred from the channel on another symbol.

In the embodiment of the present application, the port number is used as an example to identify the antenna port. The port number may also have other names, such as port index, port identification, etc., which are not specifically limited in the embodiment of the present application.

5. DMRS

The demodulation reference signal DMRS can be used to estimate the equivalent channel. For example, DMRS can be used to perform equivalent channel estimation on the physical downlink shared channel (PDSCH) in order to coherently demodulate the downlink data. Among them, PDSCH is used to carry downlink data, and DMRS is transmitted along with PDSCH. Usually DMRS is located in the first few symbols of the time slot occupied by PDSCH. In order to ensure the quality of channel estimation, different DMRS ports are usually orthogonal ports. The DMRS corresponding to different DMRS ports are orthogonal in the frequency domain, time-frequency or code domain.

Specifically, taking PDSCH as an example, channel estimation is introduced:

The DMRS and the data signals transmitted by PDSCH are precoded in the same way, so that the DMRS and the data signals experience the same The transmitting device sends DMRS and data signals to the receiving device. The vector of the DMRS sent by the transmitting device is s, and the vector of the data signal sent is x. The DMRS and the data signal are precoded in the same way (multiplied by the same precoding matrix P). Accordingly, the vector of the data signal received by the receiving device satisfies:

Wherein, y represents the vector of data signals received by the receiving device, H represents the frequency domain response of the channel between the transmitting device and the receiving device, P represents the precoding matrix used by the transmitting device, x represents the vector of data signals sent by the transmitting device, and n represents the vector of noise. Represents the equivalent channel frequency domain response between the transmitting device and the receiving device.

The vector of the DMRS received by the receiving device satisfies:

Wherein, r represents the vector of DMRS received by the receiving device, H represents the frequency domain response of the channel between the transmitting device and the receiving device, P represents the precoding matrix used by the transmitting device, s represents the vector of DMRS sent by the transmitting device, and n represents the vector of noise. Represents the equivalent channel frequency domain response between the transmitting device and the receiving device.

It can be seen from formula (1) and formula (2) that the data signal and the reference signal experience the same equivalent channel. The receiving device uses a channel estimation algorithm such as least square (LS) channel estimation and minimum mean square error (MMSE) channel estimation based on the known reference signal vector s to estimate the equivalent channel. Estimation is then performed based on the equivalent channel The estimation result is used to complete the MIMO equalization and demodulation of the data signal.

The DMRS vector can be represented as a matrix with _NR rows and R columns, that is, the dimension is _NR ×R. Among them, _NR represents the number of receiving antennas of the receiving device, and R represents the number of spatial layers. Generally speaking, one spatial layer corresponds to one DMRS port. For MIMO transmission with R spatial layers, the number of DMRS ports is R. In order to ensure the quality of channel estimation, different DMRS ports are usually orthogonal ports. The DMRS symbols corresponding to different DMRS ports are orthogonal in the frequency domain, time-frequency or code domain.

Since DMRS occupies certain time-frequency resources, in order to minimize the DMRS overhead and reduce the interference between DMRS time-frequency resources corresponding to different DMRS ports, DMRS symbols are often mapped to preset time-frequency resources through frequency division multiplexing, time division multiplexing or code division multiplexing.

Exemplarily, the NR system supports two types of DMRS resource mapping. For Type 1 DMRS, a maximum of 8 orthogonal DMRS ports can be supported; for Type 2 DMRS, a maximum of 12 orthogonal DMRS ports can be supported. For a DMRS port, in order to perform channel estimation on different time-frequency resources and ensure the quality of channel estimation, DMRS symbols need to be sent in multiple time-frequency resources. A DMRS symbol can occupy at least one orthogonal frequency division multiplexing (OFDM) symbol in the time domain, and the bandwidth occupied in the frequency domain is the same as the scheduling bandwidth of the data signal. For a DMRS port, the multiple OFDM symbols corresponding to the port correspond to the same reference signal sequence. A reference signal sequence includes multiple elements. The reference signal sequence corresponding to DMRS can be a gold sequence. Next, taking a gold sequence with a length of 31 as a pseudo-random sequence c(n), the nth element in the reference signal sequence is introduced. Among them, the nth element in the reference signal sequence satisfies:

Where r(n) represents the nth element in the reference signal sequence, n = 0, 1, ..., _MPN -1, _MPN represents the sequence length of the pseudo-random sequence c(n), c(2n) represents the 2nth element in the pseudo-random sequence, and c(2n+1) represents the 2n+1th element in the pseudo-random sequence. The pseudo-random sequence c(n) satisfies:

Where c(n) represents a pseudo-random sequence, N _c = 1600, x ₁ (n) represents the first m-sequence, x ₁ (0) = 1, x ₁ (n) = 1, n = 1, 2, ..., 30, x ₂ (n) represents the second m-sequence, and the x ₂ (n) sequence is determined by the initialization factor c _init . The initialization factor c _init of the _{x 2} (n) sequence satisfies:

Among them, c _init represents the initialization factor, Indicates the number of OFDM symbols in a time slot, represents the time slot index in a system frame, l represents the index of OFDM symbol, Indicates the sequence scrambling code identifier, represents the scrambling factor, λ represents the index of the CDM group, Indicates floor operation.

For DMRS at adjacent frequency domain locations, different scrambling factors can be used To achieve the effect of reducing PAPR. Scrambling Factor satisfy:

in, Indicates the scrambling factor. _{n SCID} indicates the scrambling factor when λ=0 or λ=2. 1-n _SCID means that when λ=1, the scrambling factor λ represents the index of the CDM group.

When the DMRS sequence initialization indication field is configured in the downlink control information (DCI) signaling, n _SCID ∈ {0, 1} may be indicated by the DCI signaling. That is, the DCI signaling indicates that the value of n _SCID is 0, or the DCI signaling indicates that the value of n _SCID is 1. In other cases, n _SCID =0 by default.

and The value of can be configured by high-level signaling. Related to the cell ID (identification), usually equal to the cell ID,

The DMRS sequence corresponding to a port is mapped to the corresponding time-frequency resource after being multiplied by the corresponding mask sequence through the preset time-frequency resource mapping rule. In the current new radio (NR) protocol, two types of DMRS configuration methods are defined, including Type 1 DMRS and Type 2 DMRS.

For port p, the mth element r(m) in the DMRS sequence corresponding to the port is mapped to the resource element (RE) with index (k,l) _p,μ according to the following rules. The RE with index (k,l) _p,μ corresponds to the OFDM symbol with index l in a time slot in the time domain and to the subcarrier with index k in the frequency domain. The mapping rules satisfy:

Formula (7):

Where p is the port number, μ is the subcarrier spacing parameter, is the DMRS modulation symbol mapped to the RE with index (k,l) _p,μ , is the symbol index of the first OFDM symbol occupied by the DMRS modulation symbol or the symbol index of the reference OFDM symbol, is the power scaling factor, w _t (l′) is the time domain mask element corresponding to the l′th OFDM symbol occupied by the DMRS modulation symbol, w _f (k′) is the frequency domain mask element corresponding to the k′th subcarrier occupied by the DMRS modulation symbol, m=2n+k′, Δ is the subcarrier offset factor. OCC includes the above time domain mask element and frequency domain mask element.

In the Type 1 DMRS mapping rule, the values of w _f (k′), w _t (l′), and Δ corresponding to the DMRS port p can be determined according to Table 1. Table 1 is described as follows:

Table 1

In Table 1, when the value of DMRS port p is 1000, the values of λ and Δ are 0. When k′＝0, the value of w _f (k′) is +1, and when k′＝1, the value of w _f (k′) is +1. When l′＝0, the value of _wt (l′) is +1, and when l′＝1, the value of _wt (l′) is +1. The other values of DMRS port p in Table 1 can be deduced by analogy and will not be described in detail.

In the Type 2 DMRS mapping rule, the values of w _f (k′), w _t (l′), and Δ corresponding to the DMRS port p can be determined according to Table 2. Table 2 is described as follows:

Table 2

In Table 2, when the value of DMRS port p is 1000, the values of λ and Δ are 0. When k′＝0, the value of w _f (k′) is +1, and when k′＝1, the value of w _f (k′) is +1. When l′＝0, the value of w _t (l′) is +1, and when l′＝1, the value of w _t (l′) is +1. The other values of DMRS port p in Table 2 can be deduced by analogy and will not be described in detail. It should be noted that for the DMRS port number of PUSCH, it can be the DMRS port number of PDSCH-1000, for example, port 0, 1, 2, etc.

According to formula (7), the time-frequency resource mapping method of type 1 DMRS is introduced as follows:

As shown in FIG2 , for a single-symbol DMRS (corresponding to l′＝0), a maximum of 4 DMRS ports are supported. Among them, the 4 DMRS ports are divided into 2 CDM groups. CDM group 0 includes port 0 and port 1, and CDM group 1 includes port 2 and port 3. CDM group 0 and CDM group 1 are frequency division multiplexed (mapped on different frequency domain resources). The DMRS ports contained in the CDM group are mapped on the same time-frequency resources. The reference signals corresponding to the DMRS ports contained in the CDM group are distinguished by OCC to ensure the orthogonality of the DMRS ports in the CDM group, thereby suppressing the interference between the reference signals transmitted on different DMRS ports. Specifically, port 0 and port 1 are located in the same RE, and resource mapping is performed in a comb-tooth manner in the frequency domain, that is, the adjacent frequency domain resources occupied by port 0 and port 1 are separated by one subcarrier. For a DMRS port, the two adjacent REs occupied correspond to an OCC codeword sequence of length 2. For example, for subcarrier 0 and subcarrier 2, port 0 and port 1 use a set of OCC codeword sequences of length 2 (+1+1 and +1-1). Similarly, port 2 and port 3 are located in the same RE and are mapped to the unoccupied REs of port 0 and port 1 in a comb-tooth manner in the frequency domain. For subcarrier 1 and subcarrier 3, port 2 and port 3 use a set of OCC codeword sequences of length 2 (+1+1 and +1-1).

As shown in FIG3 , for dual-symbol DMRS (corresponding to l′=0 and l′=1), a maximum of 8 DMRS ports are supported. Among them, the 8 DMRS ports are divided into 2 CDM groups. CDM group 0 includes port 0, port 1, port 4 and port 5, and CDM group 1 includes port 2, port 3, port 6 and port 7. CDM group 0 and CDM group 1 are frequency division multiplexed, and the reference signals corresponding to the DMRS ports contained in the CDM group are distinguished by OCC. Specifically, port 0, port 1, port 4 and port 5 are located in the same RE, and resource mapping is performed in a comb-tooth manner in the frequency domain, that is, the adjacent frequency domain resources occupied by port 0, port 1, port 4 and port 5 are separated by one subcarrier. For a DMRS port, the two adjacent subcarriers and two OFDM symbols occupied correspond to an OCC codeword sequence of length 4. For example, for subcarrier 0 and subcarrier 2 corresponding to OFDM symbol 1 and OFDM symbol 2, port 0, port 1, port 4 and port 5 use a set of OCC codeword sequences with a length of 4 (+1+1+1+1/+1+1-1-1/+1-1+1-1/+1-1-1+1). Similarly, port 2, port 3, port 6 and port 7 are located in the same RE and are mapped in a comb-tooth manner on the unoccupied subcarriers of port 0, port 1, port 4 and port 5 in the frequency domain. For subcarrier 1 and subcarrier 3 corresponding to OFDM symbol 1 and OFDM symbol 2, port 2, port 3, port 6 and port 7 use a set of OCC codeword sequences with a length of 4 (+1+1+1+1/+1+1-1-1/+1-1+1-1/+1-1-1+1).

According to formula (7), the time-frequency resource mapping method of type 2 DMRS is introduced as follows:

As shown in Figure 4, for a single-symbol Type 2 DMRS (corresponding to l′=0), a maximum of 6 DMRS ports are supported. Among them, the 6 DMRS ports are divided into 3 CDM groups, and frequency division multiplexing is used between CDM groups. The reference signals corresponding to the DMRS ports contained in the CDM group are distinguished by OCC to ensure the orthogonality of the DMRS ports in the CDM group, thereby suppressing the interference between the reference signals transmitted on different DMRS ports. Specifically, CDM group 0 includes port 0 and port 1, CDM group 1 includes port 2 and port 3, and CDM group 2 includes port 4 and port 5. Frequency division multiplexing is used between CDM groups (mapped on different frequency domain resources). The reference signals corresponding to the DMRS ports contained in the CDM group are mapped on the same time-frequency resources. The reference signals corresponding to the DMRS ports contained in the CDM group are distinguished by OCC. For a DMRS port, its corresponding DMRS is mapped in the frequency domain on multiple subcarriers containing 2 consecutive subcarriers. In the resource subblock of a wave, adjacent resource subblocks are spaced 4 subcarriers apart in the frequency domain. Specifically, port 0 and port 1 are located in the same resource element (RE), and resource mapping is performed in a comb-tooth manner. Taking the frequency domain resource granularity of 1 resource block (RB) as an example, port 0 and port 1 occupy subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7. Port 2 and port 3 occupy subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9. Port 4 and port 5 occupy subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11. For the two DMRS ports contained in a CDM group, the corresponding OCC codeword sequences of length 2 (+1+1 and +1-1) are in the two adjacent subcarriers.

As shown in FIG5A , for dual-symbol Type 2 DMRS (corresponding to l′＝0 and l′＝1), a maximum of 12 ports are supported. The 12 DMRS ports are divided into 3 CDM groups, and frequency division multiplexing is used between CDM groups. The reference signals corresponding to the DMRS ports contained in the CDM group are orthogonalized by OCC. Among them, CDM group 0 includes port 0, port 1, port 6 and port 7; CDM group 1 includes port 2, port 3, port 8 and port 9; CDM group 2 includes port 4, port 5, port 10 and port 11. Frequency division multiplexing is used between CDM groups (mapped on different frequency domain resources). The reference signals corresponding to the DMRS ports contained in the CDM group are mapped on the same time-frequency resources. The reference signals corresponding to the DMRS ports contained in the CDM group are distinguished by OCC. For a DMRS port, its corresponding DMRS is mapped in the frequency domain in multiple resource sub-blocks containing 2 consecutive sub-carriers, and the adjacent resource sub-blocks are separated by 4 sub-carriers in the frequency domain. Specifically, the ports included in a CDM group are located in the same resource element (RE), and resources are mapped in a comb-tooth manner in the frequency domain. Taking the frequency domain resource granularity of 1RB as an example, port 0, port 1, port 6 and port 7 occupy subcarrier 0, subcarrier 1, subcarrier 6 and subcarrier 7 corresponding to OFDM symbol 1 and OFDM symbol 2. Port 2, port 3, port 8 and port 9 occupy subcarrier 2, subcarrier 3, subcarrier 8 and subcarrier 9 corresponding to OFDM symbol 1 and OFDM symbol 2. Port 4, port 5, port 10 and port 11 occupy subcarrier 4, subcarrier 5, subcarrier 10 and subcarrier 11 corresponding to OFDM symbol 1 and OFDM symbol 2. For the four DMRS ports included in a CDM group, an OCC codeword sequence of length 4 (+1+1+1+1/+1+1-1-1/+1-1+1-1/+1-1-1+1) corresponds to the two adjacent subcarriers corresponding to the two OFDM symbols.

As wireless communication equipment is deployed more densely in the future and the number of terminal devices continues to grow, higher requirements are placed on the number of MIMO transmission streams. In addition, with the continuous evolution of the subsequent Massive MIMO system, the number of transmitting and receiving antennas will further increase (such as the number of transmitting antennas of network equipment supports 128T or 256T, and the number of receiving antennas of terminal equipment supports 8R), and channel information acquisition will be more accurate. It is necessary to further support a higher number of transmission streams to improve the spectrum efficiency of the MIMO system. The above aspects will inevitably require more DMRS ports to support a higher number of transmission streams (such as the number of transmission streams greater than 12). As the number of transmission streams increases, higher accuracy requirements are placed on channel estimation. However, the current maximum of 12 orthogonal ports cannot guarantee the transmission performance of more than 12 streams.

Next, a method for expanding the number of orthogonal DMRS ports is exemplarily introduced, that is, introducing more DMRS ports through code division multiplexing.

According to the NR protocol, the total number of ports supported by DMRS is related to the following two factors: DMRS configuration type, or the number of OFDM symbols occupied by DMRS in the time domain. At the same time, a DMRS configuration type and the number of time-domain OFDM symbols occupied by a type of DMRS correspond to a maximum number of DMRS ports. The number of orthogonal DMRS port combinations supported by the current NR protocol is shown in Table 3 below:

Table 3

In Table 3, when the DMRS is configured as Type 1 and a single symbol is used, a maximum of 4 ports are supported, as described in Figure 2. When the DMRS is configured as Type 1 and a double symbol is used, a maximum of 8 ports are supported, as described in Figure 3. When the DMRS is configured as Type 2 and a single symbol is used, a maximum of 6 ports are supported, as described in Figure 4. When the DMRS is configured as Type 2 and a double symbol is used, a maximum of 12 ports are supported, as described in Figure 5B.

Exemplarily, taking a single-symbol Type2 DMRS as an example, as shown in FIG5B , the left side of the figure shows the DMRS port configuration of the existing NR protocol. The upper left table in the figure shows the subcarrier ID occupied by DMRS and the corresponding port index. The figure below takes port 0 and port 1 as examples to illustrate the corresponding DMRS codeword sequence. Taking DMRS ports P0 and P1 as an example, the frequency domain subcarriers occupied in an RB are numbered {0, 1, 6, 7}, the codeword sequence corresponding to the P0 port is {+1, +1, +1, +1}, and the codeword sequence corresponding to the P1 port is {+1, -1, +1, -1}. The P1 port occupies the same time-frequency resources as the P0 port, and is transmitted on the same time-frequency resources as the P0 port through code division orthogonality.

Corresponding to the existing solution on the left, the table above and the figure below on the right give a code division multiplexing DMRS port expansion solution. On the same time-frequency resources, taking CDM group 0 as an example, corresponding to the same CDM group, a group of ports are multiplexed through code division multiplexing (2 ports for single symbol, 4 ports for double symbol), corresponding to P12 and P13 on the right side of the above figure, the corresponding codeword sequences on the subcarrier numbers {0, 1, 6, 7} are {+1, +j, -1, -j} and {+1, -j, -1, +j}. The multiplexing method of the remaining CDM groups is the same as that of CDM group 0. Through this technical means, it can be achieved The total number of DMRS ports multiplexed within the same time-frequency resources is doubled.

The following is a brief introduction to the DMRS port expansion solution for code division multiplexing.

This expansion method can be extended to single-symbol and dual-symbol, Type 1 and Type 2 of DMRS configuration through the same sequence and mapping method. Among them, the design scheme of uplink DMRS time-frequency resources and codeword sequences can adopt the Discrete Fourier Transform (DFT) sequence corresponding to Scheme 1, and the design scheme of downlink DMRS time-frequency resources and codeword sequences can adopt the Walsh sequence corresponding to Scheme 2. The following provides the port number and time-frequency resource mapping formulas corresponding to the two schemes and the values of the variables in the formulas for each port (including CDM group index and OCC value).

For the expansion of DMRS ports for code division multiplexing, a possible time-frequency resource mapping formula (8) and formula (9) are as follows:

k′＝0,1; n＝0,1,…l′＝0,1.

Formula (9):

in,

k′＝0,1,2,3; n＝0,1,…l′＝0,1.

Where p is the index of the DMRS port, μ is the subcarrier spacing parameter, is the DMRS symbol corresponding to the DMRS port p on the RE with index (k, l), is the power factor, w _t (l′) is the time domain mask sequence element corresponding to the time domain symbol indexed as l′, w _f (k′) is the frequency domain mask sequence element corresponding to the subcarrier indexed as k′. Δ is the subcarrier offset factor, It is the symbol index of the starting time domain symbol occupied by the DMRS symbol or the symbol index of the reference time domain symbol.

Wherein, corresponding to formula (9), the mask table representing the port index corresponding to the protocol can be as follows.

Corresponding to formula (8), w _f (2*(n mod 2)+k′) can be expressed as w _f (k″), and w _f (k′) and k′ in the following table can be changed to w _f (k″) and k″ respectively, that is, the value range of w _f in formula (8) and formula (9) is the same.

Solution 1: DFT sequence

Table 4-1: Parameter values corresponding to different DMRS ports (Type1-E)

Table 4-2: Parameter values corresponding to different DMRS ports (Type2-E)

Scheme 2: Walsh sequence

Table 4-3: Parameter values corresponding to different DMRS ports (Type1-E)

Table 4-4: Parameter values corresponding to different DMRS ports (Type2-E)

In one implementation, for FD-OCC expansion, a possible time-frequency resource mapping is as follows:

Formula (10):

in,

k′＝0,1; n＝0,1,…l′＝0,1.

Table 4-5

Where p is the index of the DMRS port, μ is the subcarrier spacing parameter, is the DMRS symbol corresponding to the DMRS port p on the RE with index (k, l), is the power factor, w _t (l′) is the time domain mask sequence element corresponding to the time domain symbol indexed as l′, w _f (k′) is the frequency domain mask sequence element corresponding to the subcarrier indexed as k′. Δ is the subcarrier offset factor, It is the symbol index of the starting time domain symbol occupied by the DMRS symbol or the symbol index of the reference time domain symbol. b(n mod 2) is the outer mask sequence, where for the existing DMRS port of R15, b(0)=1, b(1)=1; for the newly added DMRS port of R18, b(0)=1, b(1)=-1, or b(0)=-1, b(1)=1.

Solution 1: DFT sequence

Table 4-6: Parameter values corresponding to different DMRS ports (Type1 R18)

Table 4-7: Parameter values corresponding to different DMRS ports (Type2 R18)

Scheme 2: Walsh sequence

Table 4-8: Parameter values corresponding to different DMRS ports (Type1 R18)

Table 4-9: Parameter values corresponding to different DMRS ports (Type2 R18)

The above-mentioned code division multiplexing DMRS port expansion method can be naturally extended to single/double symbol, Type 1/2 DMRS configuration types through the same sequence and mapping method. The number of supported orthogonal DMRS port combinations is shown in Table 4-10:

Table 4-10

In Table 4-10, when DMRS is configured as Type 1 and a single symbol is used, a maximum of 8 ports are supported; when DMRS is configured as Type 1 and a double symbol is used, a maximum of 16 ports are supported. When DMRS is configured as Type 2 and a single symbol is used, a maximum of 12 ports are supported; when DMRS is configured as Type 2 and a double symbol is used, a maximum of 24 ports are supported. Exemplarily, the time-frequency resource mapping method of the extended antenna port can be shown in Table 5 below.

Table 5

At present, the NR protocol defines the DMRS symbols and time-frequency resource mapping methods corresponding to the DMRS port. During each data transmission process, the network device notifies the terminal device of the DMRS port allocated. Based on the allocated DMRS port, the terminal device performs the DMRS signal reception and channel estimation process at the corresponding resource location in accordance with the DMRS symbol generation method and time-frequency resource mapping rules defined in the protocol. The DMRS port notification method defined in the NR protocol is as follows: high-level signaling semi-statically configures the DMRS type, and DCI signaling dynamically notifies the allocated DMRS port index, which is described in detail as follows:

First, RRC signaling configures the DMRS type and the number of occupied symbols.

The DMRS type used is configured through the high-level signaling DMRS-DownlinkConfig. The specific signaling content is as follows:

Among them, the dmrs-Type field is used to indicate the DMRS type, that is, whether Type 1 DMRS or Type 2 DMRS is used. The maxLength field is used to indicate the number of symbols, that is, the maximum length of the leading symbol is 1 or 2, which can be understood as single-symbol DMRS or double-symbol DMRS. Among them, the maxLength field is len2, which means that two symbols are occupied. If the maxLength field is configured to len2, the network device can further indicate whether single-symbol DMRS or double-symbol DMRS is used through DCI signaling. If the maxLength field is not configured, 1-symbol DMRS is used.

Second, DCI signaling notifies the allocated DMRS port index.

For example, the DCI signaling may include an antenna port field. The antenna port field is used to indicate the DMRS port index, and the index value corresponds to the index of one or more DMRS ports. The NR protocol defines different DMRS port tables for different values of the dmrs-Type field and the maxLength field configuration. For the DMRS port indication corresponding to the downlink PDSCH transmission, the DMRS port indication table defined by the existing NR protocol corresponds to 2 DMRS types and 2 DMRS preamble symbol numbers as shown below.

Specifically, Table 6 illustrates a DMRS port table corresponding to dmrs-Type=1, maxLength=1.

Table 6

As shown in the table above, the first column in the table is the indicated value of the DCI field "Antenna port", corresponding to the index value indicated by each port combination, the second column indicates the number of CDM groups that do not transmit data on the DMRS symbol in the current scheduling time, and the third column is the DMRS port index scheduled by the current terminal device. According to the port index and the aforementioned mapping relationship between the port index and the time-frequency resource, the time-frequency resource can be determined. In addition, the fourth column in the table below is the number of pre-DMRS symbols currently scheduled. , the single symbol defaults to 1 and is not listed, and the double symbol corresponds to 1 or 2. Through the index value of "Antenna port", the terminal device can determine the DMRS port index corresponding to the currently scheduled PDSCH or PUSCH, and then the time-frequency resources and sequence occupied by the DMRS port, and at the same time determine the use of the time-frequency resources on the DMRS symbol, and then receive (PDSCH) or send (PUSCH) the DMRS port.

Taking Table 6 as an example, in the case of using a single codeword, the Antenna port field in the DCI signaling indicates an index value, such as indicating an index value of 3, the number of CDM groups that do not transmit data in the row where the index value 3 is located is 2, and the index of the DMRS port is 0. It can be understood that the DCI signaling indicates The number of CDM groups that do not transmit data on the symbol of the DMRS transmission indicated by the DCI signaling is 2 (or it can be understood that the number of CDM groups that transmit DMRS is 2), and the DMRS port index is 0. For another example, in the case of a single codeword, the Antenna port field in the DCI signaling indicates an index value, such as indicating an index value of 2, the number of CDM groups that do not transmit data in the row where the index value 2 is located is 1, and the index of the DMRS port is 0, 1. It can be understood that the number of CDM groups that do not transmit data on the symbol of the DMRS transmission indicated by the DCI signaling is 1 (or it can be understood that the number of CDM groups that transmit DMRS is 1), and the DMRS port index is 0, 1.

Table 7 illustrates a DMRS port table corresponding to dmrs-Type=1, maxLength=2.

Table 7

Table 8 illustrates a DMRS port table corresponding to dmrs-Type=2, maxLength=1.

Table 8

Table 9 illustrates a DMRS port table corresponding to dmrs-Type=2, maxLength=2.

Table 9

It should be noted that the index value of an "Antenna port" can only be indicated to one terminal device at a scheduling time, but for the same scheduling time, the network device can indicate multiple different "Antenna port" index values to different terminal devices. This scenario can be understood as multiple users transmitting PDSCH at the same scheduling time, that is, multi-user (Multi-User, MU) MIMO spatial division multiplexing is performed between multiple users.

In addition, according to the above four antenna port indication tables 6-9 corresponding to the prior art, it can be seen that the number of index values of "Antenna port" determines the DCI overhead of the field. For Type1 single symbol, there are 12 values from 0 to 11, so 4 bits of overhead are required; for Type1 double symbols, there are 31 values from 0 to 30, so 5 bits of overhead are required; for Type2 single symbol, there are 24 values from 0 to 23, so 5 bits of overhead are required; for Type2 double symbols, there are 58 values from 0 to 57, so 6 bits of overhead are required.

In addition, for the DMRS port indication corresponding to the uplink PUSCH transmission, one difference from the downlink DMRS port indication is that the number of layers for downlink scheduling is indicated jointly according to the DMRS port, and the number of layers for uplink scheduling is indicated separately from the DMRS port. Therefore, the DMRS port indication table of PUSCH corresponds to different port indication tables for different numbers of transmission streams (number of ranks). Below, the DMRS port indication table corresponding to the two DMRS types and two DMRS preamble symbol numbers defined in the existing NR protocol is shown.

Table 10 illustrates a DMRS port table corresponding to dmrs-Type=1, maxLength=1, and rank=1.

Table 10

Table 11 illustrates a DMRS port table corresponding to dmrs-Type=1, maxLength=1, and rank=2.

Table 11

Table 12 illustrates a DMRS port table corresponding to dmrs-Type=1, maxLength=1, and rank=3.

Table 12

Table 13 illustrates a DMRS port table corresponding to dmrs-Type=1, maxLength=1, and rank=4.

Table 13

Table 14 illustrates a DMRS port table corresponding to dmrs-Type=1, maxLength=2, and rank=1.

Table 14

Table 15 illustrates a DMRS port table corresponding to dmrs-Type=1, maxLength=2, and rank=2.

Table 15

Table 16 illustrates a DMRS port table corresponding to dmrs-Type=1, maxLength=2, and rank=3.

Table 16

Table 17 illustrates a DMRS port table corresponding to dmrs-Type=1, maxLength=2, and rank=4.

Table 17

Table 18 illustrates a DMRS port table corresponding to dmrs-Type=2, maxLength=1, and rank=1.

Table 18

Table 19 illustrates a DMRS port table corresponding to dmrs-Type=2, maxLength=1, and rank=2.

Table 19

Table 20 illustrates a DMRS port table corresponding to dmrs-Type=2, maxLength=1, and rank=3.

Table 20

Table 21 illustrates a DMRS port table corresponding to dmrs-Type=2, maxLength=1, and rank=4.

Table 21

Table 22 illustrates an example of a DMRS port table corresponding to dmrs-Type=2, maxLength=2, and rank=1.

Table 22

Table 23 illustrates a DMRS port table corresponding to dmrs-Type=2, maxLength=2, and rank=2.

Table 23

Table 24 illustrates a DMRS port table corresponding to dmrs-Type=2, maxLength=2, and rank=3.

Table 24

Table 25 illustrates a DMRS port table corresponding to dmrs-Type=2, maxLength=2, and rank=4.

Table 25

As can be seen from the table above, for the uplink DMRS port indication, the number of index values of "Antenna port" determines the DCI overhead of this field. The difference from the downlink is that the value of the uplink "Antenna port" field is determined according to the maximum overhead under each rank (for example, the rank 1 DMRS port combination overhead is generally the largest). The reason is that the rank number corresponding to the uplink PUSCH transmission is determined according to other DCI fields, while the rank number corresponding to the downlink PDSCH transmission is determined according to the "Antenna port" indication combined with the DMRS port number. For Type1 single symbol, 3 bits of overhead are required; for Type1 double symbols, 4 bits of overhead are required; for Type2 single symbol, 4 bits of overhead are required; for Type2 double symbols, 5 bits of overhead are required.

For the aforementioned code division multiplexing DMRS port expansion solution, the DMRS port is expanded from a maximum of 12 ports in the prior art to a maximum of 24 ports. For Type 1 and Type 12, as well as the four DMRS configuration combinations of single symbol and double symbol, the upper limit of the supported DMRS ports has been doubled, from a maximum of 4 ports to a maximum of 8 ports for Type 1 single symbol, from a maximum of 8 ports to a maximum of 16 ports for Type 1 double symbol, from a maximum of 6 ports to a maximum of 12 ports for Type 2 single symbol, and from a maximum of 12 ports to a maximum of 24 ports for Type 2 double symbol. For more DMRS ports, the aforementioned DCI port indication table is no longer used. The antenna port determination method provided in this application is used to maximize the port combination indication, improve the flexibility of multi-user port scheduling, and minimize the indication overhead.

The method provided in the embodiment of the present application can be used in various communication systems. For example, the communication system can be a long term evolution (LTE) system, a fifth generation (5G) mobile communication system, a wireless fidelity (WiFi) system, a communication system related to the third generation partnership project (3GPP), a future evolving communication system (such as: a sixth generation (6G) mobile communication system, etc.), or a system integrating multiple systems, etc., without limitation. The method provided in the embodiment of the present application is described below by taking the communication system 60 shown in FIG. 6 as an example. FIG. 6 is only a schematic diagram and does not constitute a limitation on the applicable scenarios of the technical solution provided in the present application.

As shown in FIG6, a schematic diagram of the architecture of a communication system 60 provided in an embodiment of the present application is shown. In FIG6, the communication system 60 may include one or more network devices 601 (only one is shown) and one or more terminals (for example, For example, terminal 602-terminal 604). The network device and the terminal have multiple transmitting antennas and receiving antennas.

In FIG6 , the network device can provide wireless access services for the terminal. Specifically, each network device corresponds to a service coverage area, and the terminal entering the area can communicate with the network device through the air interface to receive the wireless access service provided by the network device. Optionally, the service coverage area may include one or more cells. The terminal and the network device can communicate through an air interface link. Among them, the air interface link can be divided into an uplink (UL) and a downlink (DL) according to the direction of the data transmitted thereon. Uplink data sent from the terminal to the network device can be transmitted on the UL, and downlink data transmitted from the network device to the terminal can be transmitted on the DL. For example: in FIG6 , the terminal 603 is located in the coverage area of the network device 601, the network device 601 can send downlink data to the terminal 603 through the DL, and the terminal 603 can send uplink data to the network device 601 through the UL.

The network device in the embodiment of the present application, for example: the network device 601 can be any device with wireless transceiver function. Including but not limited to: the evolved base station (NodeB or eNB or e-NodeB, evolutional Node B) in LTE, the evolved base station (next generation eNB, ng-eNB) in the next generation LTE, the base station (gNodeB or gNB) or the transmission receiving point (transmission receiving point/transmission reception point, TRP) in NR, the base station of the subsequent evolution of 3GPP, the access node in the Wi-Fi system, the wireless relay node, the wireless backhaul node, etc. The base station can be: a macro base station, a micro base station, a micro-micro base station, a small station, a relay station, or a balloon station, etc. Multiple base stations can support the networks of the same technology mentioned above, or they can support the networks of the different technologies mentioned above. The base station can include one or more co-sited or non-co-sited TRPs. The network device can also be a wireless controller in the cloud radio access network (cloud radio access network, CRAN) scenario. The network device may also be a centralized unit (CU) and/or a distributed unit (DU). The network device may also be a server, a wearable device, a machine communication device, or a vehicle-mounted device. The following description is made by taking the network device as a base station as an example. The multiple network devices may be base stations of the same type or different types. The base station may communicate with the terminal or communicate with the terminal through a relay station. The terminal may communicate with multiple base stations of different technologies. For example, the terminal may communicate with a base station supporting an LTE network or a base station supporting a 5G network, and may also support dual connections with a base station of an LTE network and a base station of a 5G network. In the embodiment of the present application, the device for realizing the function of the network device may be a network device; or it may be a device capable of supporting the network device to realize the function, such as a chip system, which may be installed in the network device or used in combination with the network device. In the embodiment of the present application, the chip system may be composed of a chip, or may include a chip and other discrete devices. In the method provided in the embodiment of the present application, the method provided in the embodiment of the present application is described by taking the device for realizing the function of the network device as an example that the network device is a network device.

The terminal in the embodiments of the present application, for example: terminal 602, terminal 603 or terminal 604 is a device with wireless transceiver function, such as customer premises equipment (CPE), user equipment or relay equipment. The terminal can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on the water surface (such as ships, etc.); it can also be deployed in the air (for example, on airplanes, balloons and satellites, etc.). The terminal can also be called a terminal device, and the terminal device can be a user equipment (UE), wherein the UE includes a handheld device, a vehicle-mounted device, a wearable device or a computing device with wireless communication function. Exemplarily, the UE can be a mobile phone, a tablet computer or a computer with wireless transceiver function. The terminal device may also be a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in unmanned driving, a wireless terminal in telemedicine, a wireless terminal in a smart grid, a wireless terminal in a smart city, or a wireless terminal in a smart home, etc. In the embodiment of the present application, the device for realizing the function of the terminal may be a terminal; or it may be a device that can support the terminal to realize the function, such as a chip system, which may be installed in the terminal or used in combination with the terminal. In the embodiment of the present application, the chip system may be composed of a chip, or may include a chip and other discrete devices. In the method provided in the embodiment of the present application, the method provided in the embodiment of the present application is described by taking the device for realizing the function of the terminal as an example.

As an example but not limitation, in the present application, the terminal may be a wearable device. Wearable devices may also be referred to as wearable smart devices, which are a general term for wearable devices that are intelligently designed and developed using wearable technology for daily wear, such as glasses, gloves, watches, clothing, and shoes. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothes or accessories. For example, a wearable device is not just a hardware device, but also a device that realizes powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include devices that are fully functional, large in size, and can realize complete or partial functions without relying on smartphones, such as smart watches or smart glasses, as well as devices that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various types of smart bracelets and smart jewelry for vital sign monitoring.

In the present application, the terminal may be a terminal in the Internet of Things (IoT) system. IoT is an important part of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network of human-machine interconnection and object-to-object interconnection. The terminal in the present application may be a terminal in machine type communication (MTC). The terminal of the present application may be a vehicle-mounted module, a vehicle-mounted module, a vehicle-mounted component, a vehicle-mounted chip or a vehicle-mounted unit built into a vehicle as one or more components or units. The vehicle may implement the method of the present application through the built-in vehicle-mounted module, vehicle-mounted module, vehicle-mounted component, vehicle-mounted chip or vehicle-mounted unit. Therefore, the embodiments of the present application may be applied to vehicle networking, such as vehicle to everything (V2X), long term evolution vehicle (LTE-V), vehicle to vehicle (V2V), etc.

The communication system 60 shown in Figure 6 is only used as an example and is not used to limit the technical solution of the present application. Those skilled in the art should understand that in the specific implementation process, the communication system 60 may also include other devices, and the number of network devices and terminals may also be determined according to specific needs without limitation.

Optionally, each network element or device in Figure 6 of the embodiment of the present application (for example, network device 601, terminal 602, terminal 603 or terminal 604, etc.) can also be referred to as a communication device, which can be a general device or a special device, and the embodiment of the present application does not make any specific limitations on this.

Optionally, the relevant functions of each network element or device (e.g., network device 601, terminal 602, terminal 603, or terminal 604) in FIG. 6 of the embodiment of the present application can be implemented by one device, or by multiple devices together, or by one or more functional modules in one device, and the embodiment of the present application does not specifically limit this. It is understandable that the above functions can be network elements in hardware devices, or software functions running on dedicated hardware, or a combination of hardware and software, or virtualization functions instantiated on a platform (e.g., a cloud platform).

In a specific implementation, each network element or device shown in FIG6 (such as network device 601, terminal 602, terminal 603 or terminal 604, etc.) can adopt the composition structure shown in FIG7, or include the components shown in FIG7. FIG7 is a schematic diagram of the hardware structure of a communication device applicable to an embodiment of the present application. The communication device 70 includes at least one processor 701 and at least one communication interface 704, which are used to implement the method provided in an embodiment of the present application. The communication device 70 may also include a communication line 702 and a memory 703.

Processor 701 can be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the present application.

The communication link 702 may include a path to transmit information between the above components, such as a bus.

The communication interface 704 is used to communicate with other devices or communication networks. The communication interface 704 can be any transceiver-like device, such as an Ethernet interface, a radio access network (RAN) interface, a wireless local area network (WLAN) interface, a transceiver, a pin, a bus, or a transceiver circuit.

The memory 703 may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory may exist independently and be coupled to the processor 701 through the communication line 702. The memory 703 may also be integrated with the processor 701. The memory provided in the embodiment of the present application may generally have non-volatility.

Among them, the memory 703 is used to store the computer execution instructions involved in executing the scheme provided in the embodiment of the present application, and the execution is controlled by the processor 701. The processor 701 is used to execute the computer execution instructions stored in the memory 703, so as to implement the method provided in the embodiment of the present application. Alternatively, optionally, in the embodiment of the present application, the processor 701 may also perform the processing-related functions in the method provided in the following embodiment of the present application, and the communication interface 704 is responsible for communicating with other devices or communication networks, which is not specifically limited in the embodiment of the present application.

Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application code, which is not specifically limited in the embodiments of the present application.

The coupling in the embodiments of the present application is an indirect coupling or communication connection between devices, units or modules, which can be electrical, mechanical or or other forms for information exchange between devices, units or modules.

As an embodiment, the processor 701 may include one or more CPUs, such as CPU0 and CPU1 in FIG. 7 .

As an embodiment, the communication device 70 may include multiple processors, such as the processor 701 and the processor 707 in FIG7. Each of these processors may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. The processor here may refer to one or more devices, circuits, and/or processing cores for processing data (such as computer program instructions).

As an embodiment, the communication device 70 may further include an output device 705 and/or an input device 706. The output device 705 is coupled to the processor 701 and can display information in a variety of ways. For example, the output device 705 may be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector. The input device 706 is coupled to the processor 701 and can receive user input in a variety of ways. For example, the input device 706 may be a mouse, a keyboard, a touch screen device, a sensor device, or the like.

It is understandable that the composition structure shown in FIG. 7 does not constitute a limitation on the communication device. In addition to the components shown in FIG. 7 , the communication device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

The method provided by the embodiment of the present application will be described below in conjunction with the accompanying drawings. Each network element in the following embodiment may have the components shown in FIG7 , which will not be described in detail.

It is to be understood that in the embodiments of the present application, "transmission" can be understood as sending and/or receiving according to the specific context. "Transmission" can be a noun or a verb. When the execution subject of the action is not emphasized, "transmission" is often used instead of sending and/or receiving. For example, the phrase "transmitting PUSCH" can be understood as "sending PUSCH" from the perspective of the terminal, and can be understood as "receiving PUSCH" from the perspective of the base station. In addition, it should be pointed out that "transmitting PUSCH" can be understood by those skilled in the art as "transmitting information carried in PUSCH".

It can be understood that the message names between the network elements or the names of the parameters in the messages in the following embodiments of the present application are merely examples, and other names may be used in specific implementations, and the embodiments of the present application do not specifically limit this.

It can be understood that in the embodiments of the present application, "/" can indicate that the objects associated with each other are in an "or" relationship, for example, A/B can indicate A or B; "and/or" can be used to describe that there are three relationships between the associated objects, for example, A and/or B can indicate: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. In addition, expressions similar to "at least one of A, B and C" or "at least one of A, B or C" are usually used to indicate any of the following: A exists alone; B exists alone; C exists alone; A and B exist at the same time; A and C exist at the same time; B and C exist at the same time; A, B and C exist at the same time. The above uses A, B and C as examples to illustrate the optional items of the item. When there are more elements in the expression, the meaning of the expression can be obtained according to the above rules.

In order to facilitate the description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first", "second" and the like may be used to distinguish between technical features with the same or similar functions. The words "first", "second" and the like do not limit the quantity and execution order, and the words "first", "second" and the like do not necessarily limit the differences. In the embodiments of the present application, the words "exemplary" or "for example" are used to represent examples, illustrations or explanations, and any embodiment or design described as "exemplary" or "for example" should not be interpreted as being more preferred or more advantageous than other embodiments or design. The use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way for easy understanding.

It is understood that the "embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, the various embodiments in the entire specification do not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It is understood that in various embodiments of the present application, the size of the sequence number of each process does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

It can be understood that in this application, "if" and "if" both mean that corresponding processing will be carried out under certain objective circumstances, and do not limit the time, nor do they require judgment actions when implementing them, nor do they mean that there are other limitations.

It can be understood that in the present application, "used for indication" can include direct indication and indirect indication, and can also include explicit indication and implicit indication. When describing that a certain indication information is used to indicate A, it can include that the indication information directly indicates A or indirectly indicates A, but it does not mean that the indication information must carry A. The information indicated by a certain information (such as the first information, second information, third information, etc. described below) is called information to be indicated. In the specific implementation process, there are many ways to indicate the information to be indicated, for example but not limited to, the information to be indicated can be directly indicated, such as the information to be indicated itself or the index of the information to be indicated. It can also be The information to be indicated can be indirectly indicated by indicating other information, wherein the other information is associated with the information to be indicated. It is also possible to indicate only a part of the information to be indicated, while the other part of the information to be indicated is known or agreed in advance. For example, the indication of specific information can also be achieved by using the arrangement order of each information agreed in advance (for example, stipulated by the protocol), thereby reducing the indication overhead to a certain extent.

It can be understood that some optional features in the embodiments of the present application may be implemented independently in certain scenarios without relying on other features, such as the solution on which they are currently based, to solve corresponding technical problems and achieve corresponding effects, or may be combined with other features according to needs in certain scenarios. Accordingly, the devices provided in the embodiments of the present application may also realize these features or functions accordingly, which will not be elaborated here.

It can be understood that the same step or steps or technical features with the same functions in the embodiments of the present application can be referenced to each other in different embodiments.

It is understandable that in the embodiments of the present application, the terminal and/or the network device may perform some or all of the steps in the embodiments of the present application, and these steps are only examples, and the embodiments of the present application may also perform other steps or variations of various steps. In addition, the various steps may be performed in different orders presented in the embodiments of the present application, and it is possible that not all of the steps in the embodiments of the present application need to be performed.

Based on the above-mentioned problems, an embodiment of the present application provides a communication method. By dividing the set of antenna port combinations under different DMRS configuration types (i.e., the full set) into subsets, the network device can indicate one or more subsets of antenna port combinations to the terminal device through high-level signaling according to scheduling requirements, and then indicate one port combination in the subset of antenna port combinations. Since the number of port combination indexes in the subset of antenna port combinations is less than that in the full set, a smaller indication overhead can be used to achieve flexible scheduling of multiple users.

As shown in FIG8 , a method is provided for an embodiment of the present application. FIG8 takes a network device and a terminal as an example of the execution subject of the interaction diagram to illustrate the method, but the present application does not limit the execution subject of the interaction diagram. For example, the network device in FIG8 may also be a chip, a chip system, or a processor that supports the network device to implement the method, or a logic module or software that can implement all or part of the network device functions; the terminal in FIG8 may also be a chip, a chip system, or a processor that supports the terminal to implement the method, or a logic module or software that can implement all or part of the terminal functions. The method may include the following steps:

801: The network device sends first indication information to the terminal.

Specifically, the network device determines the terminal scheduling status within a certain scheduling time and the index of the antenna port corresponding to each scheduled terminal, and sends first indication information to the terminal to indicate the antenna port combination for sending or receiving data corresponding to the terminal.

In one embodiment, a scheduling time may be a time slot, or a time unit, a transmission time interval (TTI), a subframe, or a mini time slot, etc.

Exemplarily, the first indication information may be used to indicate a first port combination, wherein the first port combination may be a port combination in the first port combination subset.

The first port combination subset is a set including one or more antenna port combinations, such as including N antenna port combinations, each antenna port combination may include i antenna ports, and N and i are both positive integers. For example, the antenna port may be identified by a port number, such as the first port combination includes port 0 (port number 0) and port 1 (port number 1), which may be represented by [0, 1]. For example, the first port combination subset may include: {0, 1, [0, 1], [0-2], [0, 2]}.

It should be noted that the port combination [0-2] exemplified in the above embodiment of the present application can be used to indicate an antenna port combination consisting of port 0, port 1 and port 2. This will not be repeated later.

In one implementation, the first indication information may include index information of the first port combination in the first port combination subset. For example, the first indication information may include an index value of the first port combination in the first port combination subset, such as the "Antenna port" value of the first column shown in the aforementioned port indication table. After receiving the first indication information, the terminal may obtain one or more port numbers of the first port combination by querying the index value of the port combination included in the first indication information and the antenna port index table configured by the network device, i.e., the index information of the first port combination subset.

In one implementation, the first indication information may be carried in the DCI, that is, the DCI sent by the network device to the terminal may carry the first indication information for indicating the DMRS antenna port combination. For example, the DCI includes an "Antenna port" field for indicating The index value of the DMRS antenna port combination.

802: The terminal sends or receives a DMRS according to the antenna port corresponding to the first indication information.

Correspondingly, the terminal device receives the first indication information of the above step 801, determines the first antenna port combination according to the index value of the antenna port combination indicated in the first indication information, and then transmits the DMRS through one or more antenna ports in the first antenna port combination.

Among them, if at the scheduling moment, the network device indicates to the terminal the port configuration for sending DMRS by the terminal, the terminal can send DMRS according to the antenna port corresponding to the first port combination, for example, sending DMRS through PUSCH. Alternatively, if at the scheduling moment, the network device indicates to the terminal the port configuration for receiving DMRS by the terminal, the terminal can receive DMRS according to the antenna port corresponding to the first port combination. Specifically, the terminal can receive DMRS through PDSCH and perform DMRS channel estimation based on the time-frequency resources and codeword sequence corresponding to the determined DMRS port index.

In one embodiment, the method may further include the following steps:

803: The network device sends second indication information to the terminal.

The second indication information is used to indicate the antenna port configuration type and the maximum length of the preamble symbol of the port combination set, or to indicate the antenna port configuration type and the maximum length of the preamble symbol of the first port combination subset, or to indicate both of the first and the second. After receiving the second indication information, the terminal can determine the set information of the antenna port combination configured by the network device for the terminal based on the antenna port configuration type and the maximum length of the preamble symbol indicated in the second indication information, such as whether the first port combination subset is configured, or whether the port combination set is configured.

The first port combination subset is a subset in the port combination set, and the number of preamble symbols corresponding to the first port combination subset is the same as the number of preamble symbols corresponding to the port combination set. The port combination set includes M antenna port combinations, where M is a positive integer and N is less than M. In other words, the port combination set (i.e., the full set) includes M antenna port combinations with the same number of preamble symbols. The network device can indicate partial port configurations in the full set to the terminal according to the scheduling requirements of the terminal, such as one or more subsets of the full set, for example, indicating the first port combination subset including N antenna port combinations to the terminal to meet the transmission or reception requirements of the terminal.

It should be noted that, in a specific implementation, for example, if the number of prefix symbols (or maximum length) corresponding to the port combination set is 1, then the number of prefix symbols (or maximum length) corresponding to the first port combination subset is also 1; if the number of prefix symbols corresponding to the port combination set and are 1 and 2 (or the maximum length is 2), then the number of prefix symbols corresponding to the first port combination subset can be 1 and 2 (that is, the maximum length is 2).

The first port combination subset may further include a second port combination, the second port combination includes j antenna ports, the first port combination includes i antenna ports, j is a positive integer and i is not equal to j. That is, among the N port combinations included in the first port combination subset, at least two antenna port combinations have different numbers of antenna ports.

In a possible implementation manner, i and j may be equal. That is, the first port combination subset may include multiple antenna port combinations with the same number of antennas, or may include multiple antenna port combinations with different numbers of antennas.

As can be seen from the foregoing, for the uplink DMRS port configuration, the number of uplink scheduled layers is separately indicated from the DMRS port. Therefore, the DMRS port indication table of PUSCH corresponds to different port indication tables for different numbers of transmission streams (rank numbers), wherein the number of ports included in each port combination is the same, for example, for the uplink DMRS port indication table of rank=2, each port combination includes two antenna ports; for the uplink DMRS port indication table of rank=3, each port combination includes three antenna ports. Therefore, the first port combination subset in the embodiment of the present application does not include the different port indication tables corresponding to the above-mentioned different numbers of transmission streams (rank numbers).

Next, the method for determining the port combination subset of the present application is described with reference to different examples.

Method 1: Determine the first port combination subset according to the number of CDM groups that do not transmit data.

The number of CDM groups that do not transmit data corresponds to the second column “the number of CDM groups that do not transmit data” in the antenna port indication field table.

Furthermore, the first CDM group number set is equal to the second CDM group number set.

That is, the port combination set can be divided into multiple subsets according to the "number of CDM groups that do not transmit data". For example, the number of CDM groups that do not transmit data corresponding to the port combinations included in the port combination set is 1 and 2, and the number of CDM groups that do not transmit data = 1 The port combination corresponds to the first port combination subset, and the port combination with the number of CDM groups that do not transmit data = 2 corresponds to the second port combination subset. For another example, the number of CDM groups that do not transmit data corresponding to the port combinations included in the port combination set is 1, 2, and 3, and the first port combination subset may include the port combination with the number of CDM groups that do not transmit data = 1, and the port combination with the number of CDM groups that do not transmit data = 2.

For example, as shown in the above Table 4-10, when the DMRS is configured as Type 1 or eType 1 (i.e., type 1 or enhanced type 1) and is a single symbol, a maximum of 8 ports can be supported through the port expansion scheme. Table 26-1 and Table 26-2 respectively show two possible port combination sets corresponding to dmrs-Type = 1 or eType 1, maxLength = 1, including 27 or 28 port combinations, respectively.

It should be noted that the DMRS configuration of type 1 involved in the embodiments of the present application may refer to the aforementioned DMRS configuration of Type 1, or, refer to the DMRS configuration of enhanced type 1 eType 1; similarly, the DMRS configuration of type 2 may refer to the aforementioned DMRS configuration of Type 2, or, refer to the DMRS configuration of enhanced type 2 eType 2. This will not be repeated below.

It should be noted that the antenna port table here is only used as an example. For the antenna port indication of dmrs-Type=1 or eType1, maxLength=1, the port combination set may include all the port combinations in the following table, or only some of the port combinations in the following table, or other port combinations other than those in the following table. For the above three situations, the first port combination subset selection method included in the present invention is similar and can all take effect.

Table 26-1. Port combination set

Table 26-2, Port combination set

It should be noted that the three rows with index values of 9, 10 and 11 in the above table indicate that the corresponding antenna port combinations are defined as antenna port combinations for single user (SU) transmission. That is, it can be understood that when the network device indicates the antenna port combination corresponding to the above value to the terminal device, the network device will not schedule other antenna port combinations to other terminals at the same time.

Based on Table 26 (including Table 26-1 or Table 26-2), if the network device indicates all port combinations of the port combination set shown in Table 26 to the terminal device through the second indication information, such as the second indication information includes the antenna port configuration type as type 1 (Type 1), such as dmrs-Type=1, and the maximum length of the preamble symbol is 1, that is, maxLength=1, then at a certain scheduling moment, when the network device indicates one of the port combinations in Table 26 to the terminal through the first indication information, the indication overhead required for the index values 27 or 28 is 5 bits, and the indication overhead is large.

The present application reduces the number of port combinations, i.e., the index value, by indicating a subset of the port combination set, as shown in Table 27 below. The number of CDM groups that do not transmit data can be reduced. For example, Table 27 uses the second column "Number of CDM groups that do not transmit data" in Table 26 as a subset division method. The network device can indicate all port combinations of the port combination set shown in Table 27 to the terminal device through the second indication information. For example, the second indication information includes that the antenna port configuration type is type 1 (Type 1), that is, dmrs-Type = 1, and the maximum length of the leading symbol is 1, that is, maxLength = 1;

Table 27. First port combination subset

Table 28 shows the second port combination subset corresponding to the port combination with the number of CDM groups not transmitting data = 2 determined according to the first method.

Table 28. Second port combination subset

In one embodiment, the method further includes: the network device sends a third indication information to the terminal, and the third indication information is used to indicate the number of CDM groups that do not transmit data. That is, for the above-mentioned method 1, the network device can indicate to the terminal the number of CDM groups that do not transmit data corresponding to the first port combination subset, so that the terminal can determine the first port combination subset according to the antenna port configuration type indicated in the second indication information, the maximum length of the preamble symbol and the number of CDM groups that do not transmit data.

As in the above example, the number of CDM groups that do not transmit data can be 1, 2 or 3 (that is, the number of CDM groups that do not transmit data can be 1 or 2). The number of CDM groups that do not transmit data is 1, corresponding to the above Table 27, and the number of CDM groups that do not transmit data is 2, corresponding to the above Table 28. As can be seen from the above Table 26, Type 1 DMRS only contains There are two CDM groups, and the number of CDM groups that do not transmit data is 1+2, which can be understood as the full set of DMRS combinations under this type, that is, the above Table 26.

In one implementation, the second indication information or the third indication information is carried in RRC signaling, or may also be carried in a media access control control element (MAC CE). Optionally, the second indication information and the third indication information may be carried in the same RRC signaling or the same MAC CE at the same time, such as when the network device sends a first RRC or a first MAC CE to the terminal, which includes the second indication information and the third indication information.

In one implementation, a subset of any port combination can satisfy part or all of the number of ports that can be supported by the antenna port combination of the full set of port combinations.

Specifically, each antenna port combination corresponds to an antenna port number, wherein the different antenna port numbers corresponding to the N antenna port combinations in the first port combination subset constitute a first port number set. The different antenna port numbers corresponding to the M antenna port combinations in the port combination set constitute a second port number set, and the first port number set is a subset of the second port number set. In other words, each port combination corresponds to a port number value, the set of port number values corresponding to the N port combinations included in the first port combination subset is the first port number set, the set of port number values corresponding to the M port combinations included in the port combination set is the second port number set, and the first port number set is a subset of the second port number set.

Further, the first port number set is equal to the second port number set, that is, the elements in the two sets are the same. For example, the second port number set corresponding to the full set of port combinations is {1, 2, 3, 4}, and the first port number set corresponding to the first port combination subset can be {1, 2, 3}. For another example, as shown in the aforementioned Table 27, when codeword 0 is enabled and codeword 1 is not enabled, the first port number set corresponding to the first port combination subset is {1, 2, 3, 4}, and when codeword 0 is enabled and codeword 1 is enabled, the first port number set corresponding to the first port combination subset is {1, 2, 3, 4, 5, 6, 7, 8}. As shown in the aforementioned Table 26, the second port number set corresponding to the full set of port combinations is {1, 2, 3, 4}, and the first port number set is equal to the second port number set.

Exemplarily, as shown in Tables 26 to 28 above, if the antenna port configuration type of the first port combination subset is type 1, the number of ports corresponding to the multiple antenna port combinations included in the first port combination subset includes 1 to 8. Among them, if for a codeword, the number of ports corresponding to the multiple antenna port combinations included in the first port combination subset includes 1 to 4.

In one embodiment, the first indication information may also be used to indicate the number of CDM groups that do not transmit data corresponding to the first port combination. That is, when the network device indicates the port combination to the terminal by sending the first indication information to the terminal, the number of CDM groups that do not transmit data may be carried in the first indication information, so that the terminal determines the corresponding first port combination subset according to the number of CDM groups that do not transmit data, thereby further determining a group of antenna port combinations according to the index information of the port combination in the first indication information.

In the above implementation, Table 27 includes 8 index values, which need to occupy at least 3 bits in the first indication information; Table 28 includes 16 index values, which need to occupy 4 bits. Compared with the 5 bits required to directly indicate the full set of port combinations shown in Table 26, the implementation of the present application can save 1 or 2 bits of indication overhead.

In addition, the above-mentioned division and selection of DMRS port combination subsets by the number of DMRS CDM groups that do not transmit data can be applied to scenarios where multiple users correspond to different numbers of scheduled flows. Taking the Type 1 single-symbol DMRS configuration type as an example, when the network device is a terminal configuration table 27, it can be understood that the corresponding total number of paired flows is 1 to 4 (the table supports a maximum of 4 ports of DMRS).

One possible implementation is that the network device can indicate that index 0 in table 27 corresponds to port 0 for terminal device 1, that index 1 in table 27 corresponds to port 1 for terminal device 2, that index 3 in table 27 corresponds to port 8 for terminal device 3, and that index 4 in table 27 corresponds to port 9 for terminal device 4. Then, for the current slot, terminal devices 1/2/3/4 can simultaneously perform PDSCH transmission on ports 0/1/8/9 respectively on the same time-frequency resources, forming a MU pairing stream number combination of {1+1+1+1}.

Another possible implementation is that the network device can indicate that index 2 in table 27 corresponds to port [0,1] for terminal device 1, and that index 5 in table 27 corresponds to port [8,9] for terminal device 2. Then, for the current slot, terminal devices 1/2 can simultaneously perform PDSCH transmission on ports [0,1]/[8,9] on the same time-frequency resources, forming a {2+2} MU pairing stream number combination.

When the network device configures table 28 for the terminal, it can be understood that the corresponding total number of paired streams is 5 to 8 (the table supports a maximum of 8 ports of DMRS). When the network device configures total table 26 for the terminal, it can be understood that the corresponding total number of paired streams is 1 to 8 (the table supports a maximum of 8 ports of DMRS).

One possible implementation is that the network device can indicate that index 13 in table 28 corresponds to port [0, 1, 8, 9] for terminal device 1, and that index 15 in table 28 corresponds to port [2, 3, 10, 11] for terminal device 2. Then, for the current slot, terminal device 1/2 can simultaneously transmit PDSCH on ports [0, 1, 8, 9]/[2, 3, 10, 11] on the same time-frequency resource, forming a {4+4} MU configuration. Convection number combination.

Another possible implementation is that the network device can indicate that index 7 in table 28 corresponds to port 9 for terminal device 1, that index 9 in table 28 corresponds to port 11 for terminal device 2, that index 12 in table 28 corresponds to port [0,1,8] for terminal device 3, and that index 14 in table 28 corresponds to port [2,3,10] for terminal device 4. Then, for the current slot, terminal devices 1/2/3/4 can simultaneously perform PDSCH transmission on ports [0,1,8,9]/[2,3,10,11] on the same time-frequency resources, forming a MU pairing stream number combination of {1+1+3+3}.

Based on method 1, the subset division of the Type 2 single-symbol DMRS port combination introduced in the aforementioned Table 4-10 can also be introduced.

Exemplarily, as shown in the aforementioned Tables 4-10, when the DMRS is configured as Type 2 (i.e., type two) and is a single symbol, a maximum of 12 ports can be supported through the port expansion scheme. Table 29A and Table 29B respectively show two possible port combination sets corresponding to dmrs-Type = 2, maxLength = 1, which may include 57 port combinations. Table 30 shows the first port combination subset corresponding to the port combination with the number of CDM groups that do not transmit data = 1 determined in accordance with method one. Table 31 shows the second port combination subset corresponding to the port combination with the number of CDM groups that do not transmit data = 2 determined in accordance with method one. Table 32 shows the third port combination subset corresponding to the port combination with the number of CDM groups that do not transmit data = 3 determined in accordance with method one.

Table 29A, Port Combination Set

Table 29B, Port Combination Set

Table 30. First port combination subset

Table 31. Second port combination subset

Table 32. Third port combination subset

It can be seen from the above embodiments that Tables 30, 31 and 32 include 8 index values, 16 index values and 24 index values respectively, and the required indication overhead is 3 bits, 4 bits and 5 bits. Compared with Table 29 (Table 29A or Table 29B) which includes 59 index values and the required indication overhead is 6 bits, the indication overhead can be reduced by 3/2/bits respectively.

In addition, the DMRS port subset selection method of the above method 1 selects the DMRS port combination subset by the number of DMRS CDM groups that do not send data, which can be applied to the scenario where multiple users correspond to different numbers of scheduled streams, thereby supporting MU-MIMO capabilities with higher numbers of transmission streams. Taking the above-mentioned Type 2 single-symbol DMRS configuration type as an example, when the network device is a terminal configuration table 30, it can be understood that the corresponding total number of paired streams is 1 to 4 (the table supports a maximum of 4 ports of DMRS).

One possible implementation is that the network device can indicate that index 0 in table 30 corresponds to port 0 for terminal device 1, that index 1 in table 30 corresponds to port 1 for terminal device 2, that index 3 in table 30 corresponds to port 12 for terminal device 3, and that index 4 in table 30 corresponds to port 13 for terminal device 4. Then, for the current slot, terminal devices 1/2/3/4 can simultaneously perform PDSCH transmission on ports 0/1/12/13 respectively on the same time-frequency resources, forming a MU pairing stream number combination of {1+1+1+1}.

When the network device is terminal configuration table 31, it can be understood that the corresponding total number of paired streams is 5 to 8 (the table supports a maximum of 8 ports of DMRS); when the network device is terminal configuration table 32, it can be understood that the corresponding total number of paired streams is 9 to 12 (the table supports a maximum of 12 ports of DMRS); when the network device is terminal configuration table 29A/B, it can be understood that the corresponding total number of paired streams is 1 to 12 (the table supports a maximum of 12 ports of DMRS).

One possible implementation is that the network device can indicate for terminal device 1 that index 19 in table 32 corresponds to port [0, 1, 12, 13], and for terminal device 2 that index 21 in table 32 corresponds to port [2, 3, 14, 15]. Then, for the current slot, terminal devices 1/2 can simultaneously perform PDSCH transmission on ports [0, 1, 12, 13]/[2, 3, 14, 15] on the same time-frequency resources, forming a {4+4} MU pairing stream number combination.

Method 2: Divide the port combination subsets by the type of port combination.

Exemplarily, the antenna port combinations included in the port combination set are divided into the following three types:

Category 1, which only includes existing antenna port combinations and port combinations supported by existing protocols, can also be called Cat. 1. Taking Table 33 below as an example, for single-symbol DMRS type 1, the existing antenna ports are port combinations of port numbers 0, 1, 2, and 3, corresponding to port combinations of index values 0 to 11.

Category 2, only includes the antenna port combination obtained by extension, that is, in addition to the antenna port combination supported by the existing protocol, the newly added port combination consisting of the enhanced DMRS extended antenna port can also be called Cat.2. Taking the following Table 33 as an example, for the single-symbol DMRS type 1, the newly extended port number can be 8, 9, 10, 11, and the port combination corresponding to the newly added port includes index values 12 to 20, or, optionally, it can also include a port combination corresponding to the index value 27 [9,11].

Category 3, among the antenna ports included in the above-mentioned categories 1 and 2, the port combination of the newly extended ports and the existing ports in the same CDM group can also be called Cat.3. Taking the following Table 33 as an example, for the single-symbol DMRS type 1, the newly extended ports 8, 9, 10 and 11 and the existing ports 0, 1, 2 and 3, where ports 0, 1, 8, 9 are in the same CDM group, and ports 2, 3, 10, 11 are in the same CDM group. For example, the multiple ports included in the port combinations [0,1,8], [0,1,8,9] or [2,3,10,11] are all in the same CDM group, corresponding to the port combination of index values 21 to 26. Or, optionally, such as including the port combination [9,11] in the last row of Table 33, the index value of the port combination corresponding to category 3 may be 22 to 27. For details, please refer to the difference between the aforementioned Table 26-1 and Table 26-2 of the present application, and the embodiments of the present application do not make specific limitations on this.

Furthermore, the antenna port combination of class 1 can be further defined as the DMRS port that satisfies the aforementioned background technology formula (7) and Table 1/Table 2; the antenna port of class 2 can be further defined as the DMRS port that satisfies the aforementioned formula (8) or formula (9), and Tables 4-1 to 4-4, and Tables 4-6 to 4-9.

Table 33A, Port Combination Set A

It should be noted that the two columns of information "Type" and "Remarks" in the port combination indication table illustrated in the embodiment of the present application are for illustration only, and the above information may not be included in the specific implementation process, and will not be explained later.

Table 33B, Port Combination Set B

Next, in combination with the three types of antenna port combinations mentioned above, another method for dividing antenna port combination subsets provided in an embodiment of the present application is exemplarily introduced.

(1) In one embodiment, the port combination set also includes B antenna port combinations, and the port numbers corresponding to the B antenna port combinations are the antenna port numbers corresponding to the B antenna port combinations in the first port combination subset, which are associated with the first bias, and the first bias represents an offset value indicating the antenna port number, and B is a positive integer.

Further, the port numbers corresponding to the B antenna port combinations included in the port combination set can be obtained by adding the antenna port numbers corresponding to the B antenna port combinations in the first port combination subset and the first bias. That is to say, there is a certain offset value between the port numbers of some antenna port combinations in the port combination subset and the port numbers of some antenna port combinations in the antenna port full set. As can be seen from the aforementioned Table 33, the value of B can be 9, that is, the offset value of the port numbers included in the 9 port combinations corresponding to the index values 0 to 8 and the port numbers included in the 9 port combinations corresponding to the index values 12 to 20 is 8, that is, there is a certain offset between the port numbers corresponding to the two types of port combinations in the port combination set, that is, some port numbers in the port combination class 1 can be obtained according to the first bias and the port number of the port combination class 2, and vice versa, the port number of the port combination class 2 can be obtained according to the first bias and the port number of the port combination class 1.

In a possible implementation, for example: the first of the B port combinations included in the port combination set corresponds to index 0, the port combination is port 0, the first of the B port combinations in the first port combination subset corresponds to index 12 in the antenna port set, and the port combination is port 8; the third of the B port combinations included in the antenna port set corresponds to index 2, the port combination is port 0 and port 1, the first of the B port combinations in the first port combination subset corresponds to index 14 in the antenna port set, and the port combination is port 8 and port 9; the B port combinations may also include any one of indexes 0 to 8 in the antenna port set. For details, refer to the port combination set shown in Table 33 and the first port combination subset shown in Table 34, or the port combination set shown in Table 33 and the first port combination subset shown in Table 35A-1.

That is, the first port subset may include the port combination type described in category 1, or may include the port combination type described in category 2.

Exemplarily, the first port combination subset includes B antenna port combinations, that is, the antenna port combination corresponding to the above-mentioned class 1. The port combination set includes B antenna port combinations, that is, the antenna port combination corresponding to the above-mentioned class 2. The antenna port numbers corresponding to the B antenna port combinations in the first port combination subset are added to the first offset to obtain,

In one implementation, if the antenna port configuration type of the first port combination subset is DMRS type 1, the first offset may be 8 or -8.

In one implementation, if the antenna port configuration type of the first port combination subset is DMRS type 2, as shown in the aforementioned Table 29A/B, the first offset may be 12 or -12.

In a possible implementation, for example: the first of the B port combinations included in the port combination set corresponds to index 0, the port combination is port 0, the first of the B port combinations in the first port combination subset corresponds to index 24 in the antenna port set, and the port combination is port 12; the third of the B port combinations included in the antenna port set corresponds to index 2, the port combination is port 0 and port 1, and the third of the B port combinations in the first port combination subset corresponds to index 26 in the antenna port set.

(2) In one implementation, the port combination set further includes A antenna port combinations, the number of antenna ports corresponding to the A antenna port combinations is 3 or 4, and A is a positive integer.

Exemplarily, as shown in Table 33, the number of antenna ports corresponding to the six antenna port combinations whose port combination index values are 21 to 26 is 3 or 4. In addition, the number of antenna ports corresponding to the three antenna port combinations whose port combination index values are 9 to 11 is also 3 or 4. In summary, A can be 9, that is, including port combinations with index values of 9 to 11 and index values of 21 to 26.

In one implementation, the first port combination subset further includes C antenna port combinations, the number of antenna ports corresponding to the C antenna port combinations is 3 or 4, and C is a positive integer. Exemplarily, the first port combination subset may include the 6 antenna port combinations whose index values of the port combinations in Table 33 are 21 to 26. In summary, C may be 6, that is, including port combinations with index values of 21 to 26.

In one implementation, the A antenna port combinations may include C antenna port combinations.

Further, in one embodiment, multiple antenna ports corresponding to any antenna port combination in the C antenna port combinations in the first port combination subset are in the same CDM group. That is, the conditions described in class 3 of the aforementioned port combination type are met. In other words, the first port subset may include the port combination type described in class 3, such as the port combination with index values 21 to 26 in Table 33.

In one implementation, multiple antenna ports corresponding to at least one antenna port combination among the A antenna port combinations included in the port combination set are in different CDM groups, such as the port combinations with index values of 9-11 in Table 33.

Based on the above (1) and (2) about the port combination types included in the port combination set and the port combination subset, the following possible methods for dividing the port combination subset can be obtained:

1. The first port combination subset may include the port combination types described in category 1.

For the aforementioned single-symbol DMRS type 1 port combination configuration, the network device may allocate a port combination of class 1, class 2 or class 3 to the terminal as a port combination subset.

For example, the network device configures the first port combination subset with port index numbers 1 to 11 in the terminal configuration table 33 through the second indication information, and then indicates one of the 12 port combinations through the first indication information, and the indication overhead is 4 bits, as shown in the following table 34. For another example, the network device configures the first port combination subset with port index numbers 12 to 20 in the terminal configuration table 33 through the second indication information, and then indicates one of the 9 port combinations through the first indication information, and the indication overhead is 4 bits.

Table 34. Port combination subset

2. The first port combination subset may include the port combination types described in category 2 and the port combination types described in category 3.

For example, the network device configures the port combinations of class 2 and class 3 in the terminal configuration table 33 to form a first port combination subset through the second indication information, as shown in the following Table 35 (including Table 35A-1 and Table 35B-1). Then, one of the 15 or 16 port combinations is indicated through the first indication information, and the indication overhead is 4 bits.

Table 35A-1. Port combination subset

Table 35B-1. Port combination subset

Based on the above-mentioned port combination subset division, in a possible implementation, for example, the network device can indicate the port combination [9,11]/[0,1,8]/[2,3,10] corresponding to index 9/12/14 for terminal devices 1/2/3, respectively, to form a MU pairing flow number combination of {2+3+3}. For another example, the network device can indicate the port combination [0,1,8,9]/[2,3,10,11] corresponding to index 13/15 for terminal devices 1/2, respectively, to form a MU pairing flow number combination of {4+4}.

3. The first port combination subset may include the port combination types described in category 1 and the port combination types described in category 3.

For example, the network device configures the port combinations of class 1 and class 3 in the terminal configuration table 33 to form a first port combination subset through the second indication information, as shown in the following table 36 (including 36A-1 or 36B-1). Then, one of the 16 port combinations is indicated through the first indication information, and the indication overhead is 4 bits.

It should be noted that, from the above content, the three port combinations included in class 1: [0-2], [0-3] and [0,2] are suitable for single-user SU scheduling, and these three port combinations may not be included in the first port combination subset.

Table 36A-1. Port combination subset

Table 36B-2, Port Combination Subset

Further, in one embodiment, the port combination set also includes a second port combination subset, the second port combination subset includes B antenna port combinations, and the port numbers corresponding to the B antenna port combinations are obtained by adding the antenna port numbers corresponding to the B antenna port combinations in the first port combination subset and the first bias. In other words, the second port combination subset may include the port combination types described in the aforementioned class 1 or class 2, wherein the port numbers of the B port combinations are obtained by adding the antenna port numbers corresponding to the B antenna port combinations in the first port combination subset and the first bias.

In one implementation, taking the full set table 33 as an example, the first port combination subset is the aforementioned table 35B-2, and the second port combination subset is the aforementioned table 36B-2 as an example, which may include the following three specific scheduling situations:

Scheduling 1: 4 terminals form a MU pairing flow number combination of {2+2+2+2}. Among them, take the case where all 4 terminals are configured with the full set of port combinations, and the full set index corresponds to {7+8+19+20}, and the port combination corresponds to {[0,1]+[2,3]+[8,9]+[10,11]}. According to the port combination subset provided in the present application, the first port combination subset is configured for 2 terminals, and the second port combination subset is configured for the other 2 terminals. The MU scheduling capability of the above-mentioned configuration full set can also be achieved, and at the same time, the effect of reducing the DCI overhead is achieved for each terminal.

Scheduling 2: 3 terminals form a MU pairing stream number combination of {2+3+3}. Among them, take the case where all 3 terminals are configured with the full set of port combinations, and the full set index corresponds to {23+25+27}, and the port combination corresponds to {[0,1,8]+[2,3,10]+[9,11]}. According to the indication of the port combination subset provided in the present application, the first port combination subset can be configured for 2 terminals, and the second port combination subset can be configured for another terminal; or, the first port combination subset can be configured for 1 terminal and the second port combination subset can be configured for the other 2 terminals, which can also achieve the MU scheduling capability of the above-mentioned port combination, and at the same time, the effect of reducing the DCI overhead is achieved for each terminal.

Scheduling 3: 8 terminals form a MU pairing flow number combination of {1+1+1+1+1+1+1+1}. Among them, take the case where all 8 terminals are configured with the full set of port combinations, and the full set index corresponds to {3+4+5+6+15+16+17+18}, and the port combination corresponds to {0+1+2+3+8+9+10+11}. According to the indication of the port combination subset provided in the present application, 4 terminals can be equipped with the first port combination subset, and the other 4 terminals can be equipped with the second port combination subset, and the MU scheduling capability of the above-mentioned full set of configurations can also be achieved, and at the same time, the effect of reducing the DCI overhead is achieved for each terminal.

Through the above examples of several scheduling situations, it can be further explained that for all the paired UE and paired stream combinations that can be achieved by the full set, the same MU scheduling capability can be achieved through the above two subsets. At the same time, for each terminal device, The technical effect of saving DCI overhead is achieved.

In one embodiment, the antenna port set further includes a second port combination subset, the second port combination subset further includes C antenna port combinations, the number of antenna ports corresponding to any one of the C antenna port combinations is 3 or 4, and the C antenna port combinations included in the first port combination subset are the same as the C antenna port combinations included in the second port combination subset. That is, the second port subset may include C antenna port combinations with a number of antenna ports of 3 or 4, such as the six port combinations of index numbers 22-27 in the aforementioned Table 33, where C may be 6.

Combining the above division methods, we can derive the following two better port combination subset division schemes:

Solution 1: The first port combination subset includes: a port combination of class 1 + class 3; the second port combination subset includes: a port combination of class 2 + class 3.

Further, the solution 1 can also be replaced by: the first port combination subset includes: the port combination of class 1+class 3-SU; the second port combination subset includes: the port combination of class 2+class 3. For example, the network device can divide the port combination set into the aforementioned indication table 36A-1 and table 35A-1 of the port combination subset; or, divide it into the aforementioned indication table 36B-1 and table 35B-1 of the port combination subset.

Among them, SU refers to the scheduling scenario of a single user with index values 9 to 11 corresponding to the table, that is, when the network device indicates any one of the three port combinations to the terminal device, the network device will not schedule other antenna port combinations to other terminals at the same time.

Solution 2: The first port combination subset includes: a port combination of class 1; the second port combination subset includes: a port combination of class 2 + class 3.

For example, the network device may divide the port combination set into the aforementioned indication table 34 and table 35A-1 of the port combination subset, or divide into the aforementioned indication table 34 and table 35B-1 of the port combination subset).

Through the second method of dividing the port combination subsets provided in the above embodiment of the present application, the port combination set can be divided into at least one subset, reducing the number of port combinations configured for the terminal, thereby saving signaling overhead for indicating specific port combinations.

In addition, according to the classification of the three types of port combinations mentioned above, it can be seen that the capabilities of the number of transmission streams corresponding to the port combinations contained in class 1 and class 2 are basically the same, and the newly added class 3 port combination can make the DMRS port combination supporting 3 to 4 transmission streams occupy only one CDM group, thereby achieving the effect of improving spectrum efficiency and improving MU multiplexing capability.

In one implementation, the first port combination subset or the second port combination subset includes D antenna port combinations, and the number of antenna ports corresponding to the D antenna port combinations is 5 to 8. As shown in Tables 33 to 36, for a single-symbol DMRS type 1, when two codewords are enabled, the number of antenna ports corresponding to the antenna port combination is 5 to 8, and D may be 4, that is, including four antenna port combinations corresponding to index numbers 0 to 3.

In one embodiment, the DCI used to carry the first indication information may also include a transmission configuration indication (TCI) field, and all code points in the TCI field are mapped to a TCI state.

In another implementation, the port combination set provided in the embodiment of the present application is not applicable to the following scenario: when at least one code point in the TCI field included in the DCI sent by the network device to the terminal is mapped to two TCI states.

Exemplarily, based on the second division method of the port combination subsets described above, the division of the port combination subsets of the Type 2 single-symbol DMRS described in the aforementioned Table 4-10 may also be introduced.

For example, as shown in the above Table 4-10, when the DMRS is configured as Type 2 (i.e., type 2) and is a single symbol, a maximum of 12 ports can be supported through the port expansion scheme. The above Tables 29A and 29B respectively show two possible port combination sets corresponding to dmrs-Type = 2, maxLength = 1, which may include 57 port combinations. The port combination subsets are divided according to Scheme 1 or Scheme 2 in the above-mentioned method 2.

Among them, in one implementation, based on the port combination set shown in the aforementioned Table 29A, the port combination subsets are divided according to Scheme 1, and the corresponding port combination subsets can be obtained including: port combinations of class 1 + class 3-SU, and port combinations of class 2 + class 3, as shown in Table 37A-1 and Table 37A-2.

Alternatively, in one embodiment, based on the port combination set shown in the aforementioned Table 29B, the port combination subsets are divided according to Scheme 1, and the corresponding port combination subsets can be obtained including: port combinations of class 1 + class 3-SU, and port combinations of class 2 + class 3, as shown in Table 38B-1 and Table 38B-2.

In one implementation, based on the port combination set shown in Table 29A above, the port combination subsets are divided according to Scheme 2, and the corresponding port combination subsets can be obtained, including: port combinations of class 1, and port combinations of class 2 + class 3, as shown in Tables 39A-1 and As shown in Table 39A-2.

Alternatively, in one embodiment, based on the port combination set shown in the aforementioned Table 29B, the port combination subsets are divided according to Scheme 2, and the corresponding port combination subsets can be obtained including: port combinations of class 1, and port combinations of class 2 + class 3, as shown in Table 40B-1 and Table 40B-2.

Table 37A-1. First port combination subset (class 1 + class 3-SU)

Table 37A-2, Second Port Combination Subset (Class 2 + Class 3)

Table 38B-1. First port combination subset (class 1 + class 3-SU)

Table 38B-2, Second Port Combination Subset (Class 2 + Class 3)

Table 39A/B-1, First Port Combination Subset (Class 1)

Table 39A-2, Second Port Combination Subset (Class 2 + Class 3)

Table 40B-2, Second Port Combination Subset (Class 2 + Class 3)

Next, the configuration of the port combination set and the port combination subset is exemplarily introduced when the DMRS is configured as Type 1 or eType 1 (ie, Type 1 or enhanced Type 1) and is a double symbol (maxLength=2).

Method 1:

Table 41: Port combination set

Table 42-1. First port combination subset

Table 42-2, Second Port Combination Subset

Method 2:

1. The first port combination subset: Cat2+Cat3, the second port combination subset: Cat1+Cat-SU.

Table 43-1. First port combination subset

Table 43-2, Second Port Combination Subset

2. The first port combination subset: Cat2+Cat3, the second port combination subset: Cat1.

Table 44-1. First port combination subset

Table 44-2, Second Port Combination Subset

Next, the configuration of the port combination set and the port combination subset is exemplarily introduced when the DMRS is configured as Type 2 or eType 2 (ie, Type 2 or enhanced Type 2) and is a double symbol (maxLength=2).

Method 1:

Table 45: Port combination set

Table 46-1. First port combination subset

Table 46-2, Second Port Combination Subset

Table 46-3, Third Port Combination Subset

Method 2:

Table 47-1. First port combination subset

Table 47-2, Second Port Combination Subset

Table 48-1. First port combination subset

Table 48-2, Second Port Combination Subset

The various embodiments mentioned above in this application can be combined without limitation if there is no contradiction between the solutions.

The above mainly introduces the scheme provided by the embodiment of the present application from the perspective of interaction between various network elements. Accordingly, the embodiment of the present application also provides a communication device, which can be a terminal in the above method embodiment, or a device including the above terminal, or a component that can be used for the terminal; or, the communication device can be a network device in the above method embodiment, or a device including the above network device, or a component that can be used for the network device. It can be understood that in order to realize the above functions, the above terminal or network device, etc., includes a hardware structure and/or software module corresponding to each function. Those skilled in the art should easily realize that, in combination with the units and algorithm operations of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

It should be understood that the above only describes the interaction between various network elements by taking the terminal and the network device as an example. In fact, the processing performed by the above terminal is not limited to being performed by only a single network element, and the processing performed by the above network device is not limited to being performed by only a single network element. For example, the processing performed by the network device can be performed by at least one of the central unit (CU), the distributed unit (DU) and the remote unit (RU).

The embodiment of the present application can divide the functional modules of the terminal or network device according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware or in the form of software functional modules. It can be understood that the division of modules in the embodiment of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation.

For example, in the case of dividing each functional module in an integrated manner, FIG9 shows a schematic diagram of the structure of a communication device 90. The communication device 90 includes a transceiver module 901. Optionally, the communication device 90 may also include a processing module 902. The transceiver module 901, which may also be referred to as a transceiver unit, is used to perform transceiver operations, and may be, for example, a transceiver circuit, a transceiver, a transceiver or a communication interface. The processing module 902, which may also be referred to as a processing unit, may be used to perform operations other than transceiver operations, and may be, for example, a processing circuit or a processor.

In some embodiments, the communication device 90 may further include a storage module (not shown in FIG. 9 ) for storing program instructions and data.

Exemplarily, the communication device 90 is used to implement the functions of a terminal. The communication device 90 is, for example, the terminal described in the embodiment shown in FIG8 .

Among them, the transceiver module 901 is used to receive first indication information, and the first indication information is used to indicate a first port combination, wherein the first port combination includes i antenna ports, the first port combination is a port combination in a first port combination subset, the first port combination subset is a subset in a port combination set, the first port combination subset includes N antenna port combinations, the port combination set includes M antenna port combinations, i, N and M are all positive integers and N is less than M.

The first port combination subset also includes a second port combination, the second port combination includes j antenna ports, j is a positive integer and i is not equal to j; the number of preamble symbols corresponding to the first port combination subset is the same as the number of preamble symbols corresponding to the port combination set.

The transceiver module 901 is further configured to send or receive a demodulation reference signal DMRS according to the antenna port included in the first port combination.

In one implementation, the transceiver module 901 is further configured to receive second indication information, where the second indication information is used to indicate the DMRS type and the maximum length of the preamble symbol of the port combination set and/or the first port combination subset.

In one implementation, the transceiver module 901 is further configured to receive third indication information, where the third indication information is used to indicate the number of code division multiplexing (CDM) groups that do not transmit data.

In one embodiment, the port combination set also includes a second port combination subset, the second port combination subset includes B antenna port combinations, and the port number corresponding to any one of the B antenna port combinations is obtained by adding the antenna port number corresponding to any one of the B antenna port combinations in the first port combination subset to a first bias, wherein the first bias indicates an offset value of the antenna port number, and B is a positive integer.

In one implementation, if the DMRS configuration type of the first port combination subset is type one or enhanced type one, the first offset is 8 or -8.

In one implementation, if the DMRS configuration type of the first port combination subset is type 2 or enhanced type 2, the first offset is 12 or -12.

In one implementation, the first port combination subset further includes C antenna port combinations, and the number of antenna ports corresponding to any antenna port combination in the C antenna port combinations is 3 or 4.

In one implementation, the plurality of antenna port combinations corresponding to any one of the C antenna port combinations in the first port combination subset antenna ports are in the same CDM group, C is a positive integer and C is less than or equal to N.

When used to implement the functions of the terminal, regarding other functions that the communication device 90 can implement, reference may be made to the relevant introduction of the embodiment shown in FIG8 , and no further details will be given.

Alternatively, illustratively, the communication device 90 is used to implement the function of a network device. The communication device 90 is, for example, the network device described in the embodiment shown in FIG8 .

Among them, the transceiver module 901 is used to send first indication information, and the first indication information is used to indicate a first port combination, wherein the first port combination includes i antenna ports, the first port combination is a port combination in a first port combination subset, the first port combination subset is a subset in a port combination set, the first port combination subset includes N antenna port combinations, the port combination set includes M antenna port combinations, i, N and M are all positive integers and N is less than M; the first port combination subset also includes a second port combination, the second port combination includes j antenna ports, j is a positive integer and i and j are not equal; the number of preamble symbols corresponding to the first port combination subset is the same as the number of preamble symbols corresponding to the port combination set.

In one embodiment, different numbers of antenna ports corresponding to the N antenna port combinations in the first port combination subset constitute a first port number set, different numbers of antenna ports corresponding to the M antenna port combinations in the port combination set constitute a second port number set, and the first port number set is a subset of the second port number set, wherein each antenna port combination corresponds to one antenna port number.

In one implementation, the transceiver module 901 is further configured to send second indication information, where the second indication information is used to indicate the DMRS type and the maximum length of the preamble symbol of the port combination set and/or the first port combination subset.

In one embodiment, the B port combinations in the first port combination subset correspond one to one with the B port combinations in the port combination set; wherein the B port combinations in the first port combination subset include port combinations indexed as {1, 2, 3, ...B}, wherein the port number contained in the port combination corresponding to each port combination index is associated with the port number contained in the port combination with the same index in the B port combinations in the port combination set and the first bias.

In one embodiment, the port combination set also includes a second port combination subset, the second port combination subset includes B antenna port combinations, and the port number corresponding to any one of the B antenna port combinations is obtained by adding the antenna port number corresponding to any one of the B antenna port combinations in the first port combination subset to a first bias, and the first bias indicates an offset value of the antenna port number, and B is a positive integer.

When used to implement the functions of a network device, regarding other functions that the communication device 90 can implement, reference may be made to the relevant introduction of the embodiment shown in FIG8 , and no further details will be given.

In a simple embodiment, those skilled in the art may imagine that the communication device 90 may be in the form shown in Figure 7. For example, the processor 701 in Figure 7 may call the computer-executable instructions stored in the memory 703 to enable the communication device 90 to execute the method described in the above method embodiment.

Exemplarily, the functions/implementation processes of the transceiver module 901 and the processing module 902 in FIG9 can be implemented by the processor 701 in FIG7 calling the computer execution instructions stored in the memory 703. Alternatively, the functions/implementation processes of the processing module 902 in FIG9 can be implemented by the processor 701 in FIG7 calling the computer execution instructions stored in the memory 703, and the functions/implementation processes of the transceiver module 901 in FIG9 can be implemented by the communication interface 704 in FIG7.

It is understandable that one or more of the above modules or units can be implemented by software, hardware or a combination of the two. When any of the above modules or units is implemented by software, the software exists in the form of computer program instructions and is stored in a memory, and a processor can be used to execute the program instructions and implement the above method flow. The processor can be built into a SoC (system on chip) or ASIC can also be an independent semiconductor chip. In addition to the core used to execute software instructions to perform calculations or processing, the processor can also further include necessary hardware accelerators, such as field programmable gate arrays (FPGA), PLDs (programmable logic devices), or logic circuits that implement dedicated logic operations.

When the above modules or units are implemented in hardware, the hardware can be any one or any combination of a CPU, a microprocessor, a digital signal processing (DSP) chip, a microcontroller unit (MCU), an artificial intelligence processor, an ASIC, a SoC, an FPGA, a PLD, a dedicated digital circuit, a hardware accelerator or a non-integrated discrete device, which can run the necessary software or not rely on the software to execute the above method flow.

Optionally, an embodiment of the present application further provides a chip system, including: at least one processor and an interface, the at least one processor is coupled to a memory through the interface, and when the at least one processor executes a computer program or instruction in the memory, the method in any of the above method embodiments is executed. In one possible implementation, the chip system also includes a memory. Optionally, the chip system can be composed of chips, or it can include chips and other discrete devices, which is not specifically limited in the embodiments of the present application.

Optionally, an embodiment of the present application also provides a computer-readable storage medium. All or part of the processes in the above method embodiments can be completed by a computer program to instruct the relevant hardware, and the program can be stored in the above computer-readable storage medium. When the program is executed, it may include the processes of the above method embodiments. The computer-readable storage medium can be an internal storage unit of the communication device of any of the above embodiments, such as a hard disk or memory of the communication device. The above computer-readable storage medium can also be an external storage device of the above communication device, such as a plug-in hard disk equipped on the above communication device, a smart memory card (smart media card, SMC), a secure digital (secure digital, SD) card, a flash card (flash card), etc. Further, the above computer-readable storage medium can also include both the internal storage unit of the above communication device and an external storage device. The above computer-readable storage medium is used to store the above computer program and other programs and data required by the above communication device. The above computer-readable storage medium can also be used to temporarily store data that has been output or is to be output.

Optionally, the present application also provides a computer program product. All or part of the processes in the above method embodiments can be completed by a computer program to instruct related hardware, and the program can be stored in the above computer program product. When the program is executed, it can include the processes of the above method embodiments.

Optionally, an embodiment of the present application further provides a computer instruction. All or part of the processes in the above method embodiments may be completed by computer instructions to instruct related hardware (such as a computer, a processor, an access network device, a mobility management network element or a session management network element, etc.). The program may be stored in the above computer-readable storage medium or in the above computer program product.

Optionally, an embodiment of the present application further provides a communication system, including: the network device and terminal in the above embodiment.

Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

It can be understood that the same step or steps or messages with the same function in the embodiments of the present application can be referenced to each other in different embodiments.

Finally, it should be noted that the above is only a specific implementation of this application, but the protection scope of this application is not limited to Therefore, any changes or substitutions within the technical scope disclosed in this application should be included in the protection scope of this application. Therefore, the protection scope of this application should be based on the protection scope of the claims.

Claims

A communication method, characterized in that the method comprises:

receiving first indication information, where the first indication information is used to indicate a first port combination,

The first port combination includes i antenna ports, the first port combination is a port combination in a first port combination subset, the first port combination subset is a subset in a port combination set, the first port combination subset includes N antenna port combinations, the port combination set includes M antenna port combinations, i, N and M are all positive integers and N is less than M;

The first port combination subset also includes a second port combination, the second port combination includes j antenna ports, j is a positive integer and i is not equal to j; the number of preamble symbols corresponding to the first port combination subset is the same as the number of preamble symbols corresponding to the port combination set;

A demodulation reference signal DMRS is sent or received according to the antenna port included in the first port combination.
The method according to claim 1 is characterized in that the different numbers of antenna ports corresponding to the N antenna port combinations in the first port combination subset constitute a first port number set, the different numbers of antenna ports corresponding to the M antenna port combinations in the port combination set constitute a second port number set, and the first port number set is a subset of the second port number set, wherein each antenna port combination corresponds to an antenna port number.
The method according to claim 2, characterized in that the first port number set is equal to the second port number set.
The method according to any one of claims 1 to 3, characterized in that the method further comprises:

Second indication information is received, where the second indication information is used to indicate a DMRS type and a maximum length of a preamble symbol of the port combination set and/or the first port combination subset.
The method according to any one of claims 1 to 4, characterized in that the method further comprises:

Receive third indication information, where the third indication information is used to indicate the number of code division multiplexing (CDM) groups that do not transmit data.
The method according to any one of claims 1-5 is characterized in that the first indication information is also used to indicate the number of CDM groups that do not transmit data corresponding to the first port combination.
The method according to claim 4 or 5 is characterized in that the second indication information and/or the third indication information is carried in the radio resource control RRC signaling, or carried in the medium access control control unit MAC CE.
The method according to claim 7 is characterized in that the second indication information and the third indication information are carried in the first RRC signaling, or carried in the first MAC CE.
The method according to any one of claims 1 to 8 is characterized in that the first indication information includes index information of the first port combination in the first port combination subset.
The method according to any one of claims 1-9 is characterized in that the number of CDM groups that do not transmit data corresponding to the N antenna port combinations in the first port combination subset is a first CDM group number set, the number of CDM groups that do not transmit data corresponding to the M antenna port combinations in the port combination set is a second CDM group number set, and the second CDM group number set includes the first CDM group number set.
The method according to claim 10 is characterized in that the first CDM group number set is equal to the second CDM group number set.
The method according to any one of claims 1 to 9 is characterized in that the first port combination subset also includes B port combinations, all antenna port numbers corresponding to any one of the B port combinations are associated with all antenna port numbers corresponding to at least one port in the B port combinations in the port combination set and a first bias, and the first bias indicates an offset value of the antenna port number, B is a positive integer and B is less than or equal to N.
The method according to claim 12 is characterized in that the B port combinations in the first port combination subset correspond to the B port combinations in the port combination set one by one; wherein the B port combinations in the first port combination subset include port combinations indexed as {1, 2, 3, ...B}, wherein the port number contained in the port combination corresponding to each port combination index is associated with the port number contained in the port combination with the same index in the B port combinations in the port combination set and the first bias.
The method according to claim 12 or 13, characterized in that the port combination set further includes a second port combination subset, the second port combination subset further includes B port combinations, and all antenna port numbers corresponding to any one of the B port combinations are the same as all antenna port numbers corresponding to at least one port in the B port combinations in the first port combination subset. The line port number is associated with the first bias;

Wherein, the B port combinations in the second port combination subset correspond to the B port combinations in the first port combination subset one by one; wherein, the B port combinations in the second port combination subset include port combinations indexed as {1, 2, 3, ...B}, wherein the port number contained in the port combination corresponding to each port combination index is associated with the port number and the first bias contained in the port combination with the same index in the B port combinations in the first port combination subset.
The method according to any one of claims 12-14 is characterized in that if the DMRS configuration type of the first port combination subset is type one or enhanced type one, the first bias is 8 or -8, and the port number and the first bias contained in the port combination are associated with the sum of the port number and the first bias.
The method according to any one of claims 12-14 is characterized in that if the DMRS configuration type of the first port combination subset is type two or enhanced type two, the first bias is 12 or -12, and the port number and the first bias contained in the port combination are associated with the sum of the port number and the first bias.
The method according to any one of claims 1-16 is characterized in that the port combination set also includes A antenna port combinations, the number of antenna ports corresponding to any port combination in the A antenna port combinations is 3 or 4, A is a positive integer and A is less than or equal to M.
The method according to claim 17 is characterized in that the first port combination subset also includes C antenna port combinations, and the number of antenna ports corresponding to any antenna port combination in the C antenna port combinations is 3 or 4.
The method according to claim 17 is characterized in that the multiple antenna ports corresponding to any antenna port combination among the C antenna port combinations in the first port combination subset are in the same CDM group, and C is a positive integer and C is less than or equal to N.
The method according to claim 19 is characterized in that the port combination set also includes a second port combination subset, the second port combination subset also includes C antenna port combinations, the number of antenna ports corresponding to any one of the C antenna port combinations is 3 or 4, and the C antenna port combinations included in the first port combination subset are the same as the C antenna port combinations included in the second port combination subset.
The method according to any one of claims 17-20 is characterized in that the A antenna port combinations include the C antenna port combinations.
The method according to claim 21 is characterized in that the multiple antenna ports corresponding to at least one antenna port combination among the A antenna port combinations included in the port combination set are in different CDM groups; and the at least one antenna port combination does not belong to the C antenna port combinations.
The method according to claim 21 or 22 is characterized in that at least one antenna port combination among the A antenna port combinations in the port combination set except the C antenna port combinations is used for single-user transmission, or no other antenna ports are scheduled simultaneously.
The method according to any one of claims 1 to 9 is characterized in that the first port combination subset or the second port combination subset includes D antenna port combinations, and the number of antenna ports corresponding to any one of the D antenna port combinations is 5 to 8.
The method according to any one of claims 1-24 is characterized in that the first indication information is carried in downlink control information DCI.
The method according to claim 25 is characterized in that if the DCI also includes a transmission configuration indication TCI field, all code points in the TCI field are mapped to one TCI state.
A communication method, characterized in that the method comprises:

Sending first indication information, where the first indication information is used to indicate a first port combination, wherein the first port combination includes i antenna ports, the first port combination is a port combination in a first port combination subset, the first port combination subset is a subset in a port combination set, the first port combination subset includes N antenna port combinations, the port combination set includes M antenna port combinations, i, N and M are all positive integers and N is less than M; the first port combination subset also includes a second port combination, the second port combination includes j antenna ports, j is a positive integer and i and j are not equal; the number of preamble symbols corresponding to the first port combination subset is the same as the number of preamble symbols corresponding to the port combination set;

A demodulation reference signal DMRS is sent or received according to the antenna port included in the first port combination.
The method according to claim 27 is characterized in that the different numbers of antenna ports corresponding to the N antenna port combinations in the first port combination subset constitute a first port number set, and the different numbers of antenna ports corresponding to the M antenna port combinations in the port combination set The same number of antenna ports forms a second port number set, the first port number set is a subset of the second port number set, wherein each antenna port combination corresponds to one antenna port number.
The method according to claim 28, characterized in that the first port number set is equal to the second port number set.
The method according to any one of claims 27 to 29, characterized in that the method further comprises:

Second indication information is sent, where the second indication information is used to indicate the DMRS type and the maximum length of the preamble symbol of the port combination set and/or the first port combination subset.
The method according to any one of claims 27 to 30, characterized in that the method further comprises:

Receive third indication information, where the third indication information is used to indicate the number of code division multiplexing (CDM) groups that do not transmit data.
The method according to any one of claims 27-31 is characterized in that the first indication information is also used to indicate the number of CDM groups that do not transmit data corresponding to the first port combination.
The method according to claim 31 or 32 is characterized in that the second indication information and/or the third indication information is carried in the radio resource control RRC signaling, or carried in the medium access control control unit MAC CE.
The method according to claim 33 is characterized in that the second indication information and the third indication information are carried in the first RRC signaling, or are carried in the first MAC CE.
The method according to any one of claims 27 to 34, characterized in that the first indication information includes index information of the first port combination in the first port combination subset.
The method according to any one of claims 27-35 is characterized in that the number of CDM groups that do not transmit data corresponding to the N antenna port combinations in the first port combination subset is a first CDM group number set, the number of CDM groups that do not transmit data corresponding to the M antenna port combinations in the port combination set is a second CDM group number set, and the second CDM group number set includes the first CDM group number set.
The method according to claim 36 is characterized in that the first CDM group number set is equal to the second CDM group number set.
The method according to any one of claims 27-37 is characterized in that the first port combination subset also includes B port combinations, all antenna port numbers corresponding to any one of the B port combinations are associated with all antenna port numbers corresponding to at least one port in the B port combinations in the port combination set and a first bias, and the first bias indicates an offset value of the antenna port number, B is a positive integer and B is less than or equal to N.
The method according to claim 38 is characterized in that the B port combinations in the first port combination subset correspond to the B port combinations in the port combination set one by one; wherein the B port combinations in the first port combination subset include port combinations indexed as {1, 2, 3, ...B}, wherein the port number contained in the port combination corresponding to each port combination index is associated with the port number contained in the port combination with the same index in the B port combinations in the port combination set and the first bias.
The method according to claim 38 or 39 is characterized in that the port combination set also includes a second port combination subset, the second port combination subset includes B antenna port combinations, and the port number corresponding to any one of the B antenna port combinations is obtained by adding the antenna port number corresponding to any one of the B antenna port combinations in the first port combination subset to a first bias, and the first bias indicates the offset value of the antenna port number, and B is a positive integer.
The method according to any one of claims 38-40 is characterized in that if the DMRS configuration type of the first port combination subset is type one or enhanced type one, the first bias is 8 or -8.
The method according to any one of claims 38-40 is characterized in that if the DMRS configuration type of the first port combination subset is type 2 or enhanced type 2, the first bias is 12 or -12.
The method according to any one of claims 27-42 is characterized in that the port combination set also includes A antenna port combinations, the number of antenna ports corresponding to any port combination in the A antenna port combinations is 3 or 4, A is a positive integer and A is less than or equal to M.
The method according to claim 43 is characterized in that the first port combination subset also includes C antenna port combinations, and the number of antenna ports corresponding to any antenna port combination in the C antenna port combinations is 3 or 4.
The method according to claim 44 is characterized in that the multiple antenna ports corresponding to any antenna port combination among the C antenna port combinations in the first port combination subset are in the same CDM group, and C is a positive integer and C is less than or equal to N.
The method according to claim 45, characterized in that the port combination set further includes a second port combination subset, The second port combination subset also includes C antenna port combinations, the number of antenna ports corresponding to any one of the C antenna port combinations is 3 or 4, and the C antenna port combinations included in the first port combination subset are the same as the C antenna port combinations included in the second port combination subset.
The method according to any one of claims 43-46 is characterized in that the A antenna port combinations include the C antenna port combinations.
The method according to claim 47 is characterized in that the multiple antenna ports corresponding to at least one antenna port combination among the A antenna port combinations included in the port combination set are in different CDM groups; and the at least one antenna port combination does not belong to the C antenna port combinations.
The method according to claim 47 or 48 is characterized in that at least one antenna port combination among the A antenna port combinations in the port combination set except the C antenna port combinations is used for single-user transmission, or no other antenna ports are scheduled simultaneously.
The method according to any one of claims 27-35 is characterized in that the first port combination subset or the second port combination subset includes D antenna port combinations, and the number of antenna ports corresponding to any one of the D antenna port combinations is 5 to 8.
The method according to any one of claims 27-50 is characterized in that the first indication information is carried in downlink control information DCI.
The method according to claim 51 is characterized in that if the DCI also includes a transmission configuration indication TCI field, all code points in the TCI field are mapped to one TCI state.
A network device, characterized in that the network device comprises:

processor;

A memory coupled to the processor, the memory storing computer program code, the computer program code comprising instructions, which, when executed by the processor, causes the network device to perform the method according to any one of claims 1-26, or the method according to any one of claims 27-52.
A computer-readable storage medium, characterized in that the computer-readable storage medium is located in a relay device, the computer-readable storage medium stores computer program code, and the computer program code includes instructions, which, when executed, enable the relay device to execute the method as described in any one of claims 1-26, or the method as described in any one of claims 27-52.
A chip, characterized in that the chip is located in a relay device, the chip includes a processor and a memory coupled to the processor, the memory stores computer program code, and the computer program code includes instructions. When the instructions are executed by the processor, the relay device executes the method as described in any one of claims 1 to 26, or the method as described in any one of claims 27 to 52.
A communication device, characterized in that it is used to execute the method as described in any one of claims 1-26, or the method as described in any one of claims 27-52.