WO2021062767A1

WO2021062767A1 - Non-contention-based two-step random access method and apparatus, terminal, and storage medium

Info

Publication number: WO2021062767A1
Application number: PCT/CN2019/109690
Authority: WO
Inventors: 石聪
Original assignee: Oppo广东移动通信有限公司
Priority date: 2019-09-30
Filing date: 2019-09-30
Publication date: 2021-04-08
Also published as: CN113875311A; CN113875311B

Abstract

The present application relates to the technical field of mobile communications, and provides a non-contention-based two-step random access method and apparatus, a terminal, and a storage medium. The method comprises: UE sends a message A; a base station receives the message A; the base station determines whether a payload transmitted in a PUSCH for the message A is successfully received; if the base station does not successfully receive the payload, the base station sends a message B for retransmitting the payload; the terminal listens to the message B in a listening window for the message B; the terminal retransmits the payload; if the base station successfully receives the payload, the base station sends a message B used for indicating permission to access the base station; the terminal receives the message B. By sending a message B for payload retransmission to UE and retransmitting, by the UE, the payload to the base station after receiving the message B, the technical solution provided by the present application implements payload retransmission scheduling to complete a non-contention-based two-step random access process, and improves the access success rate of the non-contention-based two-step random access process.

Description

Two-step random access method, device, terminal and storage medium based on non-competition

Technical field

This application relates to the field of mobile communications, and in particular to a two-step random access method, device, terminal and storage medium based on non-competition.

Background technique

RACH (Random Access Channel) is a very important channel in the initial access process between access network equipment and UE (User Equipment, user terminal). LTE (Long-Term Evolution) uses a four-step random access mechanism based on non-competition. In some usage scenarios in the NR (New Radio) system, it will be simplified to a two-step random access based on non-competition. Entry mechanism.

The two-step random access mechanism based on non-competition mainly includes: the UE uses message A (MsgA) to send the random access preamble and payload to the access network equipment, and the access network equipment will also The message B (MsgB) is used to send the access resolution message to the UE. When the access network device only demodulates the random access preamble and fails, the access network device needs to schedule the retransmission of the load.

In the non-competition-based four-step random access mechanism, retransmission scheduling is based on TC-RNT1 (Temporary Cell Radio Network Temporary Identifier). However, in the non-competition-based two-step random access mechanism, The UE does not have TC-RNT1, so how to complete the load retransmission scheduling in the non-contention-based two-step random access mechanism is a problem to be solved urgently.

Summary of the invention

The embodiments of this application provide a non-competition-based two-step random access method, device, terminal, and storage medium, which can solve the technology of how to complete the load retransmission scheduling based on the non-competition two-step random access mechanism in related technologies. problem. The technical solution is as follows:

According to one aspect of the present application, a non-contention-based two-step random access method is provided, the method is applied to a UE, and the method includes:

Send message A, the message A includes: a random access preamble and a payload, the random access preamble is a random access preamble dedicated to the UE, and the payload is in the UE dedicated PUSCH (Physical Uplink Shared Channel, physical uplink shared channel);

In the listening window of message B, monitor the message B;

The payload is retransmitted according to the message B.

According to one aspect of the present application, there is provided a non-contention-based two-step random access device, the device comprising:

The sending module is configured to send a message A, the message A includes: a random access preamble and a payload, the random access preamble is a random access preamble dedicated to the UE, and the payload is dedicated to the UE Transmission on the PUSCH;

The monitoring module is used to monitor the message B in the monitoring window of the message B;

The retransmission module is configured to retransmit the payload according to the message B.

According to an aspect of the present application, a communication device includes a processor and a transceiver connected to the processor; wherein:

The transceiver is configured to send a message A, the message A includes: a random access preamble and a payload, the random access preamble is a random access preamble dedicated to the UE, and the payload is in the UE dedicated uplink shared channel PUSCH transmission;

The transceiver is configured to monitor the message B in the listening window of the message B;

The processor is configured to retransmit the payload according to the message B monitored by the transceiver.

According to one aspect of the present application, a computer-readable storage medium is provided. The computer-readable storage medium stores at least one instruction, at least one program, code set or instruction set, the at least one instruction, the at least A section of the program, the code set or the instruction set is loaded and executed by the processor to implement the two-step random access method based on non-competition as described above.

According to one aspect of the present application, a chip is provided, the chip includes a programmable logic circuit and/or program instructions, and when the chip is running, it is used to implement the two-step random access method based on non-competition as described above.

According to one aspect of the present application, a computer program product is provided. The computer program product includes one or more computer programs. When the computer program is executed by a processor, the computer program is used to realize the non-competitive two-step randomization as described above. Access method.

The technical solution provided by this application has at least the following technical effects:

When the base station fails to receive the load of message A in the non-contention-based two-step random access process, it sends message B for scheduling uplink resources to the UE to retransmit the load. After receiving the message B, the UE sends the message B according to the message B’s instructions and scheduling retransmit the load to the base station, thereby realizing the retransmission scheduling of the load in message A to complete the two-step random access process based on non-competition, and improve the access of the two-step random process based on non-competition. Entry success rate.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings that need to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained from these drawings without creative work.

Fig. 1 is a block diagram of a communication system provided by an exemplary embodiment of the present application;

Fig. 2 is a flowchart of a two-step random access method based on non-competition provided by an exemplary embodiment of the present application;

Fig. 3 is a flowchart of a two-step random access method based on non-competition provided by another exemplary embodiment of the present application;

FIG. 4 is a flowchart of a two-step random access method based on non-competition provided by another exemplary embodiment of the present application;

Fig. 5 is a flowchart of a two-step random access method based on non-competition provided by another exemplary embodiment of the present application;

Fig. 6 is a block diagram of a two-step random access device based on non-competition provided by an exemplary embodiment of the present application;

Fig. 7 is a block diagram of a two-step random access device based on non-competition provided by another exemplary embodiment of the present application;

FIG. 8 is a block diagram of a two-step random access device based on non-competition provided by another exemplary embodiment of the present application;

FIG. 9 is a block diagram of a two-step random access device based on non-competition provided by another exemplary embodiment of the present application;

Fig. 10 is a block diagram of a communication device provided by an exemplary embodiment of the present application.

Detailed ways

The exemplary embodiments will be described in detail here, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings indicate the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the application as detailed in the appended claims.

Fig. 1 shows a block diagram of a communication system provided by an exemplary embodiment of the present application. As shown in FIG. 1, the communication system may include: an access network 10 and a terminal 20.

The access network 10 includes several access network devices 11. The access network 10 can be called NG-RAN (New Generation-Radio Access Network) in the 5G NR system; the access network device 11 can be a base station, and the base station 11 is a type of A device in the network 10 that provides a wireless communication function for the terminal 20. The base station 11 includes various forms of macro base stations, micro base stations, relay stations, access points, and so on. In systems using different wireless access technologies, the names of devices with base station functions may be different. For example, in LTE systems, they are called eNB (evolved NodeB); in 5G NR systems, they are called gNodeB or gNB. (next generation NodeB). As communication technology evolves, the description of "base station" may change. For convenience, in the embodiments of the present application, the above-mentioned devices providing wireless communication functions for the terminal 20 are collectively referred to as access network equipment.

The number of terminals 20 is usually multiple, and one or more terminals 20 may be distributed in a cell managed by each access network device 11. The terminal 20 may include various handheld devices with wireless communication functions, vehicle-mounted devices, wearable devices, computing devices or other processing devices connected to a wireless modem, as well as various forms of UE, MS (Mobile Station, mobile station), etc. . For ease of description, the devices mentioned above are collectively referred to as terminals. The access network device 11 and the terminal 20 communicate with each other through a certain aerial technology, such as a Uu interface.

In the communication process between the terminal 20 and the access network device 11, once the terminal 20 finds a cell, it may access the cell by connecting to the access network device 11 of the cell, and the terminal 20 and the access network device 11 The process of connecting is called a random access process. Assuming that cell A and cell B are different cells, when the terminal 20 enters cell B from cell A, it needs to switch the connection with the access network device 11 of cell A to the access network device 11 of cell B The process in which the terminal 20 switches between different access network devices 11 is called a non-contention-based random access process.

At present, the non-competition-based random access process includes a non-competition-based four-step random access process and a non-competition-based two-step random access process. The technical solution of the embodiment of the present application can be applied to a non-competition-based two-step random access process. During the access process, it can also be applied to other non-competition-based random access processes in subsequent evolution, which is not limited in the embodiment of the present application.

The "5G NR system" in the embodiments of this application may also be referred to as a 5G system or an NR system, but those skilled in the art can understand its meaning. The technical solution described in the embodiment of this application may be applicable to the 5G NR system, and may also be applicable to the subsequent evolution system of the 5G NR system, which is not limited in the embodiment of this application.

In the traditional four-step random access mechanism based on non-contention, the UE sends a message 1 including a random access preamble to the base station. After receiving the message 1, the base station sends a message 2 including a random access response to the UE, and the UE receives After message 2, message 3 including identity information (or other payload) is sent to the base station. After receiving message 3, the base station sends message 4 including an access resolution message to the UE. Among them, the identity information is UE ID (User Equipment Identify, user equipment identity information), for example, UE ID can be C-RNTI (Cell Radio Network Temporary Identifier, cell radio network temporary identifier), TC-RNTI, or RA -RNTI (Random Access Radio Network Temporary Identifier, Random Access Radio Network Temporary Identifier), etc.

In the non-contention-based two-step random access mechanism, in the non-contention-based four-step random access mechanism, the message 1 and message 3 sent by the UE to the base station are combined into message A, and the message 2 and message 2 sent by the base station to the UE Message 4 is merged into message B described below.

It should be noted that the following exemplary embodiments of the present application only take the non-contention-based random access method as the non-contention-based two-step random access method and the application of the UE to access the base station as an example for illustration. After understanding the technical solution of this application, personnel will easily think of using the non-competition-based random access method provided by this application as other non-competition-based random access methods for subsequent evolution, and applying it to other terminals to access other access methods. In the case of networked equipment, such as MS accessing base stations, etc., these extension schemes should be included in the protection scope of this application.

Please refer to FIG. 2, which shows a flowchart of a two-step random access method based on non-contention provided by an exemplary embodiment of the present application. This method can be applied to the system architecture shown in Figure 1. The method can include the following steps (201～208):

Step 201, the UE sends a message A.

Since the non-contention-based two-step random access mechanism is often used in the cell handover process, message A is mainly configured in the handover (HandOver, HO) command message. The handover command is used to control the UE to perform cell handover, that is, the UE and the cell The connection between the base stations of A is switched to the connection between the UE and the base stations of cell B.

Message A includes: random access preamble and payload. The random access preamble is a dedicated random access preamble configured by the network for the UE. The payload is transmitted on the dedicated uplink shared data channel PUSCH configured by the base station for the UE. It mainly includes the handover command completion message and possible user plane data.

After the MAC layer generates the MAC PDU corresponding to the payload of message A, the UE stores the MAC PDU (Media Access Control Protocol Data Unit, the protocol data unit of the media access control layer) in a fixed HARQ (Hybrid Auto Repeat Request, hybrid). Automatic retransmission request) buffer (buffer), such as message A buffer (or message 3 buffer). The HARQ process ID that transmits the MAC PDU is a fixed HARQ process ID, such as HARQ process ID 0.

Step 202: The base station receives message A.

In step 203, the base station judges whether the load transmitted in the PUSCH of the message A is successfully received; if so, step 204 is executed; if not, step 207 is executed.

Step 204: When the base station fails to successfully receive the load, it sends a message B for retransmitting the load.

After receiving message A, the base station decodes or decodes message A. When the base station does not decode the PUSCH, that is, when it fails to receive the load, the base station sends message B to the UE to schedule the retransmission of the load. Message B is the response of the base station to message A, and message B is used to directly or indirectly schedule uplink resources for retransmission of the load, so as to achieve the purpose of retransmission of the load.

It should be noted that, because message A includes the UE-specific random access preamble, even if the base station fails to receive the load transmitted in PUSCH, that is, the base station fails to decode the load transmitted in PUSCH, the base station can Identify the UE according to message A, and obtain the C-RNTI of the UE. Therefore, regardless of whether the base station can decode the load transmitted in the PUSCH, the base station can send a message B to the UE. Optionally, the message B includes a random access response and a random access method.

Step 205: The terminal monitors the message B in the listening window of the message B.

In the embodiment of this application, after the UE finishes sending message A, it will start a message B listening window. In the message B listening window, the UE can blindly check the PDCCH (Physical Downlink Control Channel), where: PDCCH is scrambled through RNTI (Radio Network Temporary Identifier), that is, PDCCH is addressed through RNTI.

It should be noted that step 204 can be implemented after step 201, after step 202, or after step 203. The drawing of step 204 after step 201 in FIG. 2 is only an exemplary description. The application is not limited.

Step 206: The terminal retransmits the payload.

After receiving the message B sent by the base station, the terminal can retransmit the load according to the uplink resources directly or indirectly scheduled by the message B to complete the non-contention-based two-step random access process, that is, the UE completes the cell handover.

Step 207: When the base station successfully receives the load, it sends a message B for indicating permission to access the base station.

Exemplarily, the message B used to indicate permission to access the base station does not carry the UL grant.

Step 208: The terminal receives message B.

In summary, the technical solution provided by the embodiments of the present application, when the base station fails to successfully receive the load of the message A in the non-contention-based two-step random access process, it sends the uplink resource for scheduling to the UE to achieve load control. Retransmitted message B. After receiving the message B, the UE retransmits the load to the base station according to the instructions and scheduling of the message B, thereby realizing the retransmission scheduling of the load in the message A to complete the two-step random access based on non-contention The process improves the access success rate of a two-step random process based on non-competition.

When the above message B is used to schedule the retransmission of the load, there are at least the following three different implementation methods:

1. The DCI in message B is scrambled by C-RNTI, and the DCI schedules downlink transmission;

2. The DCI in message B is scrambled by MsgB-RNTI (such as RA-RNTI), and the DCI schedules downlink transmission.

3. The DCI in message B is scrambled by C-RNTI, and the DCI schedules uplink transmission.

Three different implementations are described below.

Regarding the above-mentioned first possible implementation manner, as shown in FIG. 3, the above-mentioned method may include the following steps:

Step 201, the UE sends a message A.

Since the two-step random access mechanism based on non-competition is mainly used in the process of RRC connected cell handover, message A is mainly configured in the handover (HO) command message, which is used to control the UE to perform cell handover, i.e. The connection between the UE and the base station of cell A is switched to the connection between the UE and the base station of cell B.

Message A includes: random access preamble and payload, where the random access preamble is a dedicated random access preamble configured by the network for the UE, and the payload is transmitted on the dedicated uplink shared data channel PUSCH configured by the network for the UE. It mainly includes the handover command completion message and possible user plane data.

After the MAC layer generates the MAC PDU corresponding to the message A payload, the UE saves the MAC PDU in a MAC PDU in a fixed HARQ buffer, such as the message A buffer (or the message 3 buffer). The HARQ process ID that transmits the MAC PDU is a fixed HARQ process ID, such as HARQ process ID 0.

Step 202: The base station receives message A.

Step 2041: The base station determines the C-RNTI of the UE according to the UE-specific random access preamble.

C-RNTI is configured in the handover command. Since the random access preamble is a UE-specific preamble, the base station can determine the C-RNTI of the UE according to the UE-specific random access preamble. The C-RNTI can be used to address the PDCCH, that is, it can be scrambled. PDCCH.

Step 2042: The base station sends a message B, where the message B is a PDCCH scrambled by C-RNTI.

In the embodiment of this application, the PDCCH includes DCI (Downlink Control Information, downlink control command), which is used to schedule downlink transmission. DCI is the downlink control information sent by the base station to the UE. The DCI can be used to schedule uplink transmission or Can be used to schedule downlink transmission.

When DCI is used for scheduling downlink transmission, the base station sends downlink information to the UE on the downlink resources scheduled by the DCI; when the DCI is used for scheduling uplink transmission, the UE sends uplink information to the base station on the uplink resources scheduled by the DCI.

In the embodiment of this application, the DCI in the PDCCH is used to schedule downlink transmission.

Step 2051, the UE monitors the message B in the listening window of the message B;

The UE receives message B, obtains DCI according to the PDCCH in message B, and receives downlink data according to DCI scheduling.

The UE will start a listening window after sending message A. In this listening window, the UE can blindly detect the PDCCH. In the embodiment of this application, the PDCCH is scrambled by C-RNTI, and the DCI contained in the PDCCH contains DA (Downlink Assignment, downlink assignment), the DA is scheduled for PDSCH (Physical Downlink Shared Channel, physical downlink shared channel).

Step 2043: The base station sends a MAC PDU on the downlink resource scheduled by the PDCCH.

The base station sends the MAC PDU on the downlink resources scheduled by the DCI in the PDCCH.

Step 2052: The UE receives and decodes the MAC PDU.

The embodiment of the application does not limit the content contained in the MAC PDU. Optionally, the MAC PDU may include TAC (Timing Alignment Command), or TAC and UL grant (Up Link grant, uplink scheduling resource). ), can also include fallback RAR (fallback RAR).

In an example, when the MAC PDU includes TAC and UL grant, the TAC and UL grant can carry the same MAC CE (Media Access Control Control Element, Media Access Control Control Element) in the MAC PDU. It can also be carried in different MAC CEs in MAC PDU. Among them, TAC is a timing alignment command used to align the time domain timing of the base station and the UE.

Optionally, the UL grant is used to schedule uplink resources for retransmission of the load.

In another example, when the MAC PDU includes a fallback RAR, the fallback RAR is used to indicate that the UE needs to retransmit the load, and the fallback RAR includes at least UL grant, TAC, and TC-RNTI.

Exemplarily, if the MAC PDU includes TAC and UL grant, or the MAC PDU includes a fallback RAR, it indicates that the UE needs to retransmit the load.

Step 206: If the MAC PDU carries a UL grant, the UE retransmits the load on the uplink resource scheduled by the UL grant.

After the UE decodes the MAC PDU, if the MAC PDU carries the UL grant, it indicates that the UE needs to retransmit the load to the base station, and the UE retransmits the load according to the uplink resource scheduled by the UL grant.

The MAC layer of the UE obtains the stored MAC PDU from the message A buffer (or the message 3 buffer) storing the payload, and transmits the MAC PDU in the UL grant.

Exemplarily, the message B used to indicate permission to access the base station is also a PDCCH scrambled by using C-RNTI, and the DCI in the PDCCH is used to schedule downlink transmission.

Exemplarily, if the MAC PDU sent by the downlink transmission scheduled by the DCI includes TAC, but does not include UL grant or fallback RAR, it means that the base station has successfully received the load. At this time, the UE does not need to retransmit the load, and the UE clears it for transmission. After loading the HARQ buffer, the non-contention-based two-step random access process can be completed.

Step 208: The terminal receives message B.

In summary, the technical solution provided by the embodiments of this application carries a PDCCH including DCI in message B. The base station sends a MAC PDU on the downlink resources scheduled by the DCI, and the UE decodes the MAC PDU after receiving the MAC PDU. Determine whether to retransmit the load according to the content of the MAC PDU indicated by the decoding result, and provide a method to determine whether the load needs to be retransmitted. If the load needs to be retransmitted, the UE retransmits the load to the base station to achieve non-contention based The two-step random access process.

In the second possible implementation manner, based on the embodiment shown in FIG. 3, when the base station fails to successfully receive the load, steps 2041 to 2043 can be implemented alternatively to the above method, which may include the following steps: As shown in Figure 4:

Step 204a: The base station determines the msgB-RNTI (message B Radio Network Temporary Identifier, the radio network temporary identifier of the message B) of the UE according to the UE-specific random access preamble.

msgB-RNTI is the temporary wireless network identifier corresponding to message B. When the base station fails to receive the load, the base station determines the msgB-RNTI of the UE according to the random access time-frequency resource position used by the UE to transmit the dedicated random access preamble, and the msgB-RNTI can scramble the PDCCH. When the base station successfully receives the load, the base station determines the C-RNTI of the UE according to the UE-specific random access preamble, and the C-RNTI can scramble the PDCCH. That is, when the base station successfully receives the load, it uses the C-RNTI to scramble the PDCCH; when the base station fails to receive the load, it uses the msgB-RNTI to scramble the PDCCH.

Optionally, the calculation method of msgB-RNTI is the same as the calculation method of RA-RNTI. RA-RNTI is a temporary wireless network identification in a four-step random access mechanism based on non-competition. The RA-RNTI is determined by the PRACH (Physical Random Access Channel) time-frequency resource location that carries message 1. When the calculation method of msgB-RNTI is the same as the calculation method of RN-RNTI, the calculation formula of the msgB-RNTI is as follows:

msgB-RNTI=1+s_id+14×t_id+14×f_id+14×80×8×ul_carrier_id

Among them, s_id is the index of the first OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing) symbol specifying PRACH (Physical Random Access Channel) (0≤s_id<14), and t_id is the system Specify the index of the first time slot of PRACH in the frame (0≤t_id<80), f_id is the value of PRACH specified in the index frequency domain (0≤f_id<8), and ul_carrier_id is used for message A (or message 1) UL (Uplink) carrier to be transmitted (0 means NUL (Normal Uplink) carrier, 1 means SUL (Supplementary Uplink) carrier).

Step 204b, the base station sends a message B, where the message B is a PDCCH scrambled by MsgB-RNTI.

Step 205a: In the listening window of the message B, the UE monitors both the msgB-RATI scrambled PDCCH and the C-RNTI scrambled PDCCH at the same time.

After sending message A, the UE will start a listening window, in which the UE can blindly check the PDCCH. In the embodiment of the present application, when the base station fails to receive the load successfully, the PDCCH uses msgB-RNTI for scrambling, and when the base station successfully receives the load, the PDCCH uses C-RNTI for scrambling. In the listening window of message B, the UE monitors both the msgB-RATI scrambled PDCCH and the C-RNTI scrambled PDCCH. If the UE monitors the msgB-RNTI scrambled PDCCH, it means that the UE needs to retransmit the payload. ; If the UE monitors the PDCCH scrambled by the C-RNTI, it means that the network has successfully received msgA.

The UE receives message B, obtains DCI according to the PDCCH in message B, and receives downlink data according to DCI scheduling. The DCI included in the PDCCH includes DA, and the PDSCH is scheduled in the DA.

Step 204c: The base station sends a MAC PDU on the downlink resource scheduled by the PDCCH.

In an example, when the MAC PDU includes TAC and UL grant, the TAC and UL grant can carry the same MAC CE (Media Access Control Control Element, Media Access Control Control Element) in the MAC PDU. It can also be carried in different MAC CEs in MAC PDU. Among them, TAC is a time alignment command used to align the time domain timing of the base station and the UE.

Compared with the previous embodiment, the UE does not need to decode the MAC PDU and can determine whether the payload needs to be retransmitted according to the MsgB-RNTI. If the base station successfully receives the load, the PDCCH in message B is scrambled with C-RNTI; if the base station fails to receive the load, the PDCCH in message B is scrambled with msgB-RNTI. When the UE receives the message B, it can determine whether the load needs to be retransmitted according to the scrambling mode of the PDCCH in the message B. If the UE needs to retransmit the load to the base station, the UE retransmits the load according to the uplink resource scheduled by the UL grant carried in the MAC PDU.

In summary, the technical solution provided by the embodiments of this application uses different methods to scramble the PDCCH according to whether the base station successfully receives the load. If the base station successfully receives the load, the C-RNTI is used to scramble the PDCCH. When receiving the load, the msgB-RNTI is used to scramble the PDCCH, so that when the UE receives the message B including the PDCCH, it does not need to be decoded to determine whether the load needs to be retransmitted, which improves the speed of determining whether to retransmit the load.

In the second possible implementation manner, as shown in FIG. 5, the above method includes the following steps:

Step 201, the UE sends a message A.

After the payload generates a MAC PDU at the MAC layer, the UE saves the MAC PDU in a MAC PDU in a fixed HARQ buffer, such as the message A buffer (or the message 3 buffer). The HARQ process ID that transmits the MAC PDU is a fixed HARQ process ID, such as HARQ process ID 0.

Step 202: The base station receives message A.

Step 204A: The base station determines the C-RNTI of the UE according to the UE-specific random access preamble.

Step 204B, the base station sends message B, where message B is a PDCCH scrambled by C-RNTI.

In the embodiment of the present application, the PDCCH includes DCI, which is used to schedule downlink transmission, and DCI is downlink control information sent by the base station to the UE, and the DCI includes UL grant, which is used to schedule uplink resources.

Optionally, the DCI may also include an instruction indicating uplink timing alignment, that is, TAC.

In an example, when the HARQ process ID contained in the DCI is the same as the HARQ process ID used by the payload, the UE determines that the UL grant is used to schedule the uplink resource to retransmit the payload. Optionally, the HARQ process ID used by the payload is fixed HARQ process ID.

In another example, when the new data indication (NDI) is carried in the DCI, and the new data indication is used to indicate retransmission, the UE determines that the UL grant is used to schedule the uplink resource retransmission load. For example, when the bit value of the NDI is 0, the NDI is used to indicate retransmission; or, when the bit value of the NDI is 1, the NDI is used to indicate retransmission. It should be noted that the value of NDI is not used here to indicate retransmission.

Step 205: The UE monitors the message B in the listening window of the message B;

The UE will start a listening window after sending message A. In this listening window, the UE can blindly detect the PDCCH. In the embodiment of this application, the PDCCH is scrambled by C-RNTI, and the DCI contained in the PDCCH includes UL grant.

Step 206: The UE retransmits the load according to the uplink resource scheduled by the UL grant.

The payload transmitted in the PDSCH of message A is stored in a fixed HARQ buffer, such as the message A buffer.

The UE retransmits the load on the uplink resource scheduled by the UL grant.

Exemplarily, the message B used to indicate permission to access the base station is also a PDCCH scrambled by C-RNTI, and the DCI in the PDCCH includes TAC.

Step 208: The terminal receives message B.

In summary, in the technical solution provided by the embodiments of the present application, by carrying the UL grant in the DCI, the message B sent by the base station to the UE includes the PDCCH containing the DCI, so that after the UE receives the DCI, it is based on the UL grant in the DCI. The uplink resource retransmission load scheduled by grant extends a load retransmission method to complete the two-step random access process based on non-competition, and further improve the access success rate of the two-step random process based on non-competition.

It should be noted that, in the foregoing method embodiment, the technical solution of the present application is introduced and explained only from the perspective of the interaction between the base station and the UE. The above steps performed by the base station can be separately implemented as a two-step random access method based on non-competition on the base station side, and the steps performed by the UE concerned can be separately implemented as a two-step random access method based on non-contention on the UE side.

The following are device embodiments of this application, which can be used to execute the method embodiments of this application. For details not disclosed in the device embodiment of this application, please refer to the method embodiment of this application.

Please refer to FIG. 6, which shows a block diagram of a non-contention-based two-step random access device provided by an exemplary embodiment of the present application. The device 600 has the function of realizing the above-mentioned method embodiment on the UE side, and the function can be realized by hardware, or by hardware executing corresponding software. The apparatus 600 may include: a sending module 610, a monitoring module 620, and a retransmission module 630.

The sending module 610 is configured to send a message A, the message A includes: a random access preamble and a payload, where the random access preamble is a UE-specific random access preamble, and the payload is on the UE-specific uplink shared channel PUSCH transmission.

The monitoring module 620 is configured to monitor the message B in the monitoring window of the message B.

The retransmission module 630 is configured to retransmit the load when the message B is used to schedule the retransmission of the load.

Optionally, as shown in FIG. 7, the device 600 further includes a receiving module 640: the receiving module 640 is configured to: when the message B is a downlink control channel PDCCH scrambled by the cell radio network temporary identifier C-RNTI, And when the PDCCH schedules downlink transmission, the protocol data unit MAC PDU of the media intervention control layer is received according to the downlink resource scheduled by the PDCCH; the retransmission module 630 is configured to carry the uplink scheduling authorization UL in the MAC PDU When granting, the load is retransmitted on the uplink resource scheduled by the UL grant.

Optionally, as shown in FIG. 7, the apparatus 600 further includes a receiving module 640: the receiving module 640 is configured to: when the message B is the downlink control channel PDCCH scrambled by the wireless network temporary identifier msgB-RNTI of the message B And when the PDCCH schedules downlink transmission, it receives the protocol data unit MAC PDU of the media intervention control layer according to the downlink resource scheduled by the PDCCH; the retransmission module 630 is configured to carry the uplink scheduling authorization in the MAC PDU When the UL grant, the load is retransmitted on the uplink resource scheduled by the UL grant.

Optionally, the calculation method of the msgB-RNTI is the same as the calculation method of the random access wireless network temporary identifier RN-RNTI.

Optionally, the MAC PDU also carries: a timing alignment command TAC.

Optionally, the same or different media intervention control layer control unit MAC CE carried in the MAC PDU and the TAC and the UL grant; or, the TAC and the UL grant are carried in the MAC PDU The fallback random access response in the fallback RAR.

Optionally, the retransmission module 630 is further configured to: when the message B is a downlink control channel PDCCH scrambled by the cell radio network temporary identification C-RNTI, and the PDCCH is used for scheduling uplink transmission, according to the The UL grant indicated by the PDCCH retransmits the payload; wherein the hybrid automatic repeat request HARQ process ID associated with the UL grant is the same as the fixed HARQ process ID used by the payload, or the PDCCH carries a new data indication, so The new data indication is used to indicate retransmission.

In summary, the technical solution provided by the embodiments of the present application sends a message B for scheduling uplink resources to the UE to retransmit the load when the base station fails to successfully receive the load, and the UE sends the message B to the base station after receiving the message B. The load is retransmitted, thereby realizing the retransmission scheduling of the load to complete the two-step random access process based on non-competition, and improve the access success rate of the two-step random process based on non-competition.

Please refer to FIG. 8, which shows a block diagram of a two-step random access device based on non-contention provided by an exemplary embodiment of the present application. The device 800 has the function of realizing the above method embodiment on the base station side, and the function can be realized by hardware, or by hardware executing corresponding software. The device 800 may include: a message receiving module 810 and a message sending module 820.

The message receiving module 810 is configured to receive message A, the message A includes: a random access preamble and a payload, where the random access preamble is a UE-specific random access preamble, and the payload is on the UE-specific uplink shared channel PUSCH Upload

The message sending module 820 is configured to send a message B when the load is not successfully received, and the message B is used to schedule retransmission of the load.

Optionally, as shown in FIG. 9, the message sending module 820 includes: an identification determining module 821, configured to determine the cell radio network temporary identification C-RNTI of the UE according to the random access preamble; an information sending module 822. The message B is used to send a message B. The message B is a downlink control channel PDCCH scrambled by the cell radio network temporary identifier C-RNTI. The downlink control information DCI in the PDCCH is used to schedule downlink transmission; the data sending module 823 uses When downlink transmission is scheduled on the PDCCH, a protocol data unit MAC PDU of the media intervention control layer is received according to the downlink resource scheduled by the PDCCH, and the MAC PDU carries an uplink scheduling authorization UL grant.

Optionally, as shown in FIG. 9, the message sending module 820 includes: an identification determining module 821, configured to determine the message B wireless network temporary identifier msgB-RNTI of the UE according to the random access preamble; The module 822 is used to send message B, the message B is a downlink control channel PDCCH scrambled by the wireless network temporary identifier msgB-RNTI of the message B, and the downlink control information DCI in the PDCCH is used to schedule downlink transmission; data retransmission module 823, configured to receive a protocol data unit MAC PDU of the media intervention control layer on the downlink resource scheduled by the PDCCH, where the MAC PDU carries an uplink scheduling authorization UL grant.

Optionally, the MAC PDU also carries: a timing alignment command TAC.

Optionally, the message sending module 820 includes: an identification determining module 821, configured to determine the cell radio network temporary identification C-RNTI of the UE according to the random access preamble; and a data sending module 824, configured to send messages B. The message B is a downlink control channel PDCCH scrambled by the message B radio network temporary identifier msgB-RNTI, the PDCCH is used to schedule downlink transmission, and the UL grant indicated by the PDCCH is used to schedule uplink transmission; The HARQ process ID associated with the UL grant is the same as the fixed HARQ process ID used by the payload, or the PDCCH carries a new data indication, and the new data indication is used to indicate retransmission.

It should be noted that the device provided in the embodiment of the present application, when implementing its functions, only uses the division of the above-mentioned functional modules for illustration. In actual applications, the above-mentioned functions can be allocated by different functional modules as needed. That is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the apparatus and method embodiments provided in the above embodiments belong to the same concept, and the specific implementation process is detailed in the method embodiments, which will not be repeated here.

Please refer to FIG. 10, which shows a block diagram of a communication device provided by an exemplary embodiment of the present application. For example, the communication device may be the access network device 11 in the block diagram of the communication system shown in FIG. 1, such as a base station, which is used to execute the aforementioned two-step random access method based on non-competition on the base station side; or it may be as shown in FIG. The terminal 20 in the block diagram of the communication system, such as a UE, is used to execute the aforementioned two-step random access method based on non-contention on the UE side. Specifically:

The processor 1001 includes one or more processing cores, and the processor 1001 executes various functional applications and information processing by running software programs and modules.

The receiver 1002 and the transmitter 1003 may be implemented as a transceiver 1006, which may be a communication chip.

The memory 1004 is connected to the processor 1001 through a bus 1005.

In addition, the memory 1004 can be implemented by any type of volatile or non-volatile storage device or a combination thereof. The volatile or non-volatile storage device includes but is not limited to: RAM (Random-Access Memory, random access memory) And ROM (Read-Only Memory), EPROM (Erasable Programmable Read-Only Memory, Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory, Electrically Erasable Programmable Read-Only Memory) Storage), flash memory or other solid-state storage technology, CD-ROM, DVD (Digital Video Disc, high-density digital video disc) or other optical storage, tape cartridges, magnetic tape, disk storage or other magnetic storage devices. among them:

The transceiver 1006 is configured to send a message A. The message A includes a random access preamble and a payload. The random access preamble is a random access preamble dedicated to the UE. The UE is transmitted on the dedicated uplink shared channel PUSCH.

The transceiver 1006 is configured to monitor the message B in the listening window of the message B.

The processor 1001 is configured to retransmit the payload according to the message B monitored by the transceiver.

Optionally, the transceiver 1006 is configured to schedule according to the PDCCH when the message B is a downlink control channel PDCCH scrambled by the cell radio network temporary identification C-RNTI, and the PDCCH is used for scheduling downlink transmission The downlink resource receives the media intervention control layer protocol data unit MAC PDU; the processor 1001 is configured to retransmit on the uplink resource scheduled by the UL grant when the uplink scheduling authorization UL grant is carried in the MAC PDU The load.

Optionally, the transceiver 1006 is configured to: when the message B is a downlink control channel PDCCH scrambled by the message B radio network temporary identifier msgB-RNTI, and the PDCCH is used for scheduling downlink transmission, according to the PDCCH The scheduled downlink resource receives the protocol data unit MAC PDU of the media intervention control layer; the processor 1001 is configured to, when the uplink scheduling authorization UL grant is carried in the MAC PDU, reproduce the uplink resource scheduled by the UL grant Pass the load.

Optionally, the MAC PDU also carries: a timing alignment command TAC.

Optionally, the processor 1001 is configured to, when the message B is a downlink control channel PDCCH scrambled by the cell radio network temporary identification C-RNTI, and the PDCCH is used for scheduling uplink transmission, according to the PDCCH indication The UL grant retransmits the payload; wherein the HARQ process ID associated with the UL grant is the same as the HARQ process ID used by the payload.

Optionally, the processor is configured to, when the message B is a downlink control channel PDCCH scrambled by the cell radio network temporary identifier C-RNTI, and the PDCCH is used to schedule uplink transmission, according to the indication of the PDCCH UL grants retransmission of the payload; wherein, the PDCCH carries a new data indication, and the new data indication is used to indicate retransmission.

In the embodiment of the present application, a computer-readable storage medium is also provided. The computer-readable storage medium stores at least one instruction, at least one program, code set, or instruction set. A piece of program, the code set or the instruction set is loaded and executed by the processor to realize the two-step random access method based on non-contention on the UE side.

In the embodiment of the present application, a computer-readable storage medium is also provided. The computer-readable storage medium stores at least one instruction, at least one program, code set, or instruction set. A piece of program, the code set or the instruction set is loaded and executed by the processor to implement the non-contention-based two-step random access method on the base station side.

In an embodiment of the present application, a chip is also provided. The chip includes a programmable logic circuit and/or program instructions. When the chip is running, it is used to implement non-competition-based two-step random access on the UE side as described above.入方法。 Entry method.

In the embodiment of the present application, a chip is also provided. The chip includes a programmable logic circuit and/or program instructions. When the chip is running, it is used to implement non-competition-based two-step random access on the base station side as described above.入方法。 Entry method.

In the embodiment of the present application, a computer program product is also provided. When the computer program product is executed by the processor of the UE, it is used to implement the two-step random access method based on non-competition on the UE side.

In the embodiments of the present application, a computer program product is also provided. When the computer program product is executed by the processor of the base station, it is used to implement the non-competition-based two-step random access method on the base station side.

It should be understood that the "plurality" mentioned herein refers to two or more. "And/or" describes the association relationship of the associated objects, indicating that there can be three types of relationships, for example, A and/or B, which can mean: A alone exists, A and B exist at the same time, and B exists alone. The character "/" generally indicates that the associated objects before and after are in an "or" relationship.

The above are only exemplary embodiments of this application and are not intended to limit this application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included in the protection of this application. Within range.

Claims

A two-step random access method based on non-competition, characterized in that the method is applied to a user equipment UE, and the method includes:

Send message A, the message A includes: a random access preamble and a payload, the random access preamble is a random access preamble dedicated to the UE, and the payload is on the UE dedicated uplink shared channel PUSCH Upload

In the listening window of message B, monitor the message B;

The payload is retransmitted according to the message B.
The method according to claim 1, wherein the retransmitting the load when the message B is used to schedule the load for retransmission comprises:

When the message B is the downlink control channel PDCCH scrambled by the cell radio network temporary identification C-RNTI, and the PDCCH is used for scheduling downlink transmission, the protocol data unit of the media intervention control layer is received according to the downlink resource scheduled by the PDCCH MAC PDU;

When the uplink scheduling grant UL grant is carried in the MAC PDU, the load is retransmitted on the uplink resources scheduled by the UL grant.
The method according to claim 1, wherein the retransmitting the load when the message B is used to schedule the load for retransmission comprises:

When the message B is the downlink control channel PDCCH scrambled by the message B radio network temporary identifier msgB-RNTI, and the PDCCH is used for scheduling downlink transmission, receive media intervention control layer protocol data according to the downlink resources scheduled by the PDCCH Unit MAC PDU;

When the uplink scheduling grant UL grant is carried in the MAC PDU, the load is retransmitted on the uplink resources scheduled by the UL grant.
The method according to claim 3, wherein the calculation method of the msgB-RNTI is the same as the calculation method of the random access wireless network temporary identifier RN-RNTI.
The method according to any one of claims 2 to 4, wherein the MAC PDU also carries: a timing alignment command TAC.
The method of claim 5, wherein:

The same or different media intervention control layer control unit MAC CE carried in the MAC PDU and the TAC and the UL grant;

or,

The TAC and the UL grant carry the fallback random access response fallback RAR in the MAC PDU.
The method according to claim 1, wherein the retransmitting the load when the message B is used to schedule the load for retransmission comprises:

When the message B is the downlink control channel PDCCH scrambled by the cell radio network temporary identifier C-RNTI, and the PDCCH is used for scheduling uplink transmission, the load is retransmitted according to the UL grant indicated by the PDCCH;

Wherein, the HARQ process ID of the hybrid automatic retransmission request associated with the UL grant is the same as the HARQ process ID used by the payload.
The method according to claim 1, wherein said retransmitting said payload according to said message B comprises:

When the message B is the downlink control channel PDCCH scrambled by the cell radio network temporary identifier C-RNTI, and the PDCCH is used for scheduling uplink transmission, the load is retransmitted according to the UL grant indicated by the PDCCH;

Wherein, the PDCCH carries a new data indication, and the new data indication is used to indicate retransmission.
A two-step random access device based on non-competition, characterized in that the device comprises:

The sending module is configured to send a message A, the message A includes: a random access preamble and a payload, the random access preamble is a random access preamble dedicated to the UE, and the payload is dedicated to the UE Transmitted on the uplink shared channel PUSCH;

The monitoring module is used to monitor the message B in the monitoring window of the message B;

The retransmission module is configured to retransmit the payload according to the message B.
The device according to claim 9, wherein the device further comprises a receiving module:

The receiving module is configured to receive media according to the downlink resource scheduled by the PDCCH when the message B is the downlink control channel PDCCH scrambled by the cell radio network temporary identifier C-RNTI, and the PDCCH is used for scheduling downlink transmission The MAC PDU of the protocol data unit involved in the control layer;

The retransmission module is configured to retransmit the load on the uplink resource scheduled by the UL grant when the MAC PDU carries an uplink scheduling authorization UL grant.
The device according to claim 9, wherein the device further comprises a receiving module:

The receiving module is configured to receive according to the downlink resource scheduled by the PDCCH when the message B is a downlink control channel PDCCH scrambled by the message B radio network temporary identifier msgB-RNTI, and the PDCCH is used for scheduling downlink transmission The MAC PDU of the protocol data unit of the media intervention control layer;

The retransmission module is configured to retransmit the load on the uplink resource scheduled by the UL grant when the MAC PDU carries an uplink scheduling authorization UL grant.
The apparatus according to claim 11, wherein the calculation method of the msgB-RNTI is the same as the calculation method of the random access wireless network temporary identifier RN-RNTI.
The device according to any one of claims 10 to 12, wherein the MAC PDU further carries: a timing alignment command TAC.
The device of claim 13, wherein:

The same or different media intervention control layer control unit MAC CE carried in the MAC PDU and the TAC and the UL grant;

or,

The TAC and the UL grant carry the fallback random access response fallback RAR in the MAC PDU.
The device according to claim 9, wherein the retransmission module is further configured to:

When the message B is the downlink control channel PDCCH scrambled by the cell radio network temporary identifier C-RNTI, and the PDCCH is used for scheduling uplink transmission, the load is retransmitted according to the UL grant indicated by the PDCCH;

Wherein, the HARQ process ID of the hybrid automatic retransmission request associated with the UL grant is the same as the HARQ process ID used by the payload.
The device according to claim 9, wherein the retransmission module is further configured to:

When the message B is the downlink control channel PDCCH scrambled by the cell radio network temporary identifier C-RNTI, and the PDCCH is used for scheduling uplink transmission, the load is retransmitted according to the UL grant indicated by the PDCCH;

Wherein, the PDCCH carries a new data indication, and the new data indication is used to indicate retransmission.
A communication device, characterized in that, the communication device includes a processor and a transceiver connected to the processor; wherein:

The transceiver is configured to send a message A, the message A includes: a random access preamble and a payload, the random access preamble is a random access preamble dedicated to the UE, and the payload is in the UE dedicated uplink shared channel PUSCH transmission;

The transceiver is configured to monitor the message B in the listening window of the message B;

The processor is configured to retransmit the payload according to the message B monitored by the transceiver.
The communication device according to claim 17, wherein:

The transceiver is configured to receive media according to the downlink resource scheduled by the PDCCH when the message B is the downlink control channel PDCCH scrambled by the cell radio network temporary identifier C-RNTI, and the PDCCH is used for scheduling downlink transmission The MAC PDU of the protocol data unit involved in the control layer;

The processor is configured to retransmit the load on the uplink resource scheduled by the UL grant when the MAC PDU carries an uplink scheduling authorization UL grant.
The communication device according to claim 17, wherein:

The transceiver is configured to receive according to the downlink resource scheduled by the PDCCH when the message B is the downlink control channel PDCCH scrambled by the message B radio network temporary identifier msgB-RNTI, and the PDCCH is used for scheduling downlink transmission The MAC PDU of the protocol data unit of the media intervention control layer;

The processor is configured to retransmit the load on the uplink resource scheduled by the UL grant when the MAC PDU carries an uplink scheduling authorization UL grant.
The communication device according to claim 19, wherein the calculation method of the msgB-RNTI is the same as the calculation method of the random access wireless network temporary identifier RN-RNTI.
The communication device according to any one of claims 18 to 20, wherein the MAC PDU also carries: a timing alignment command TAC.
The communication device according to claim 21, wherein:

The same or different media intervention control layer control unit MAC CE carried in the MAC PDU and the TAC and the UL grant;

or,

The TAC and the UL grant carry the fallback random access response fallback RAR in the MAC PDU.
The communication device according to claim 17, wherein:

The processor is configured to retransmit according to the UL grant indicated by the PDCCH when the message B is the downlink control channel PDCCH scrambled by the cell radio network temporary identifier C-RNTI, and the PDCCH is used for scheduling uplink transmission The load;

Wherein, the HARQ process ID of the hybrid automatic retransmission request associated with the UL grant is the same as the HARQ process ID used by the payload.
The communication device according to claim 17, wherein:

The processor is configured to retransmit according to the UL grant indicated by the PDCCH when the message B is the downlink control channel PDCCH scrambled by the cell radio network temporary identifier C-RNTI, and the PDCCH is used for scheduling uplink transmission The load;

Wherein, the PDCCH carries a new data indication, and the new data indication is used to indicate retransmission.
A computer-readable storage medium, wherein at least one instruction, at least one program, code set or instruction set is stored in the computer-readable storage medium, the at least one instruction, the at least one program, the The code set or the instruction set is loaded and executed by the processor to implement the non-contention-based two-step random access method according to any one of claims 1 to 7.