KR100945098B1 - Method and Apparatus for supporting Collaborative MIMO in Wireless Communication System - Google Patents

Abstract

A method and apparatus for supporting or performing C-MIMO in a wireless communication system are disclosed. To this end, the method comprises: arranging the plurality of C-MIMO capable terminals using location information or channel quality information; Grouping each of a plurality of terminals selected from among the sorted terminals except for the highest priority terminal and the highest priority terminal; And transmitting a message including burst allocation information for the grouped terminals to efficiently use resources for C-MIMO.

Description

Method and Apparatus for supporting C-MIAO in wireless communication system TECHNICAL FIELD

BRIEF DESCRIPTION OF THE DRAWINGS The figure explaining the outline of a general SISO system and a MIMO system.

2 is a diagram illustrating a C-MIMO system performed between two terminals and one base station in a MIMO system according to an embodiment of the present invention.

3 illustrates a frame structure used in a portable Internet system for supporting IEEE 802.16d / e.

4 is a diagram illustrating a base station for supporting C-MIMO according to an embodiment of the present invention.

FIG. 5 is a configuration diagram illustrating the scheduler of FIG. 4. FIG.

6 illustrates a method of grouping C-MIMO terminals in a base station according to an embodiment of the present invention.

7 illustrates a method of grouping C-MIMO terminals in a base station according to another embodiment of the present invention.

8 is a diagram illustrating a burst allocation method according to an embodiment of the present invention.

9 illustrates a pilot pattern applied to an uplink PUSC mode in a 2x2 MIMO system according to an embodiment of the present invention.

10 is a diagram illustrating a burst allocation method according to another embodiment of the present invention.

FIG. 11 illustrates a method for supporting C-MIMO according to an embodiment of the present invention. FIG.

12 is a flowchart illustrating a scheduling method for supporting C-MIMO according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

110: interface 120: band signal processing unit

130: transmitter 140: antenna

150: scheduler 160: receiving unit

151: C-MIMO search unit 152: C-MIMO alignment unit

153: C-MIMO group unit 154: resource allocation unit

155: parameter acquisition unit

The present invention relates to a method and apparatus for supporting and performing Collaborative MIMO (C-MIMO) in a wireless communication system, and more particularly, to a method and apparatus for scheduling in a C-MIMO wireless communication system. A method and apparatus for performing C-MIMO.

Recently, as the necessity of transmitting a large amount of data at high speed using a wireless channel is rapidly increasing, a wireless / high speed data transmission system for actively supporting a mobile Internet service in a mobile environment is being actively researched. In order to support mobile Internet services, multiple input multiple output (MIMO) systems are emerging.

1 is a view for explaining the outline of a general SISO system and MIMO system.

As shown in FIG. 1A, a single input single output (SISO) system uses a single antenna (RxAnt, TxAnt) at a receiving side and a transmitting side, respectively, and includes, for example, one antenna (RxAnt). A signal is transmitted and received through one channel H formed between a base station and a terminal having one antenna TxAnt. In this SISO system, multipath phenomena occur due to obstacles in the propagation paths such as hills, valleys, and pylons, causing problems due to fading. do.

Multiple Input Multiple Output (MIMO) is a technology that transmits data through multiple paths by increasing the number of antennas of a base station and a terminal, and reduces interference by detecting signals received on each path at a receiving end, and reducing space-time diversity and Spatial multiplexing can improve transmission efficiency. For example, FIG. 1 (b) illustrates a 2x2 MIMO system using a base station having two antennas RxAnt0 and RxAnt1 and a terminal having two antennas TxAnt0 and TxAnt1. As shown in b), there are four channels between the first and second antennas RxAnt0 and RxAnt1 of the base station and the first and second antennas TxAnt0 and TxAnt1 of the terminal, that is, the first channel H00 and the first. Two channels H01, a third channel H10, and a fourth channel H11 are formed. Such a MIMO system has a higher data rate by including a plurality of transmit and receive antennas, which is advantageous in that the capacity of the radio link is improved in comparison with the SISO system in the transmit and receive period. That is, in a multipath-rich environment, multiple orthogonal channels can be created between transceivers so that data for a single user can be transmitted over the air in parallel over orthogonal channels using the same bandwidth at the same time. High spectral efficiency is achieved.

However, in the uplink of the 2 × 2 MIMO system, as described above, two antennas must be provided in each terminal, and thus, there are various difficulties, such as the power loss of the terminal and the complexity of the terminal hardware. Therefore, C-MIMO has been researched to increase the transmission rate like the conventional MIMO by using a terminal having a simpler hardware structure and one antenna, and more efficient methods for performing such C-MIMO are required.

The present invention was devised to meet the above requirements, and an object of the present invention is to provide a method and apparatus for supporting and performing C-MIMO in a wireless communication system.

Another object of the present invention is to provide a scheduling method and apparatus for supporting C-MIMO in a wireless communication system.

Another object of the present invention is to provide a scheduling method and apparatus for optimally grouping cooperative terminals for supporting C-MIMO in a wireless communication system.

It is still another object of the present invention to provide a scheduling method and apparatus for optimally grouping cooperative terminals in a C-MIMO wireless communication system and efficiently allocating resources for the grouped terminals.

For the above purpose, a method for supporting Collaborative MIMO (hereinafter referred to as C-MIMO) in a wireless communication system of one embodiment of the present invention includes a plurality of C-MIMO-capable terminals. Sorting using quality information; Grouping each of a plurality of terminals selected from among the sorted terminals except for the highest priority terminal and the highest priority terminal; And transmitting a message including burst allocation information for the grouped terminals.

In addition, the uplink scheduling method in a Collaborative MIMO (hereinafter referred to as C-MIMO) wireless communication system according to another aspect of the present invention, (a) in the current frame, a plurality of C-MIMO capable terminals Aligning to group each of the first plurality of terminals selected except the first priority terminal and the first priority terminal, and transmitting first burst allocation information for the grouped terminals; And (b) in the next frame, selecting a first terminal group to which the highest burst is assigned among the grouped terminals, and excluding the second priority terminal and the second priority terminal except the first terminal group. Regrouping each of the selected second plurality of terminals, and transmitting second burst allocation information for the first terminal group and the regrouped terminals.

On the other hand, a method for supporting C-MIMO of one embodiment of the present invention comprises the steps of: receiving a registration message including terminal information from a plurality of terminals, respectively; And at least one subburst area in the burst area allocated to the first terminal supporting Collaborative MIMO (hereinafter, referred to as C-MIMO) selected based on the terminal information. And transmitting an uplink map message so that another terminal supporting the same use the same.

In addition, a method for supporting C-MIMO according to another aspect of the present invention includes a second terminal in which a first terminal supporting Collaborative MIMO (hereinafter referred to as C-MIMO) supports C-MIMO from a base station; Receiving a message for allocating the same uplink subburst region as the terminal; And transmitting, by the first terminal, data and pilots having a pilot pattern different from that of the second terminal by using the subburst region according to the message.

On the other hand, in the method for performing Collaborative MIMO (hereinafter referred to as C-MIMO) in a wireless communication system of one embodiment of the present invention, a terminal forms a pair with a first terminal and includes a first frame of an uplink frame. Transmitting data and pilot of the terminal to a base station using an uplink burst region; And pairing, by the terminal, with a second terminal, and transmitting data and pilot of the terminal to the base station by using a second uplink burst region of the uplink frame, wherein the first uplink burst The pilot pattern of the terminal in the region and the second uplink burst region is characterized in that the same.

On the other hand, the uplink scheduling apparatus in the Collaborative MIMO (hereinafter referred to as C-MIMO) wireless communication system of one embodiment of the present invention is selected based on information on the C-MIMO capable terminals. A C-MIMO group unit for grouping each of the C-MIMO capable first terminals selected except for the first terminal and the first terminal; And a resource allocator for allocating a burst area for the grouped terminals.

On the other hand, the base station in the Collaborative MIMO (hereinafter referred to as C-MIMO) wireless communication system of one embodiment of the present invention receives a registration message including terminal information from a plurality of terminals, respectively. Way; And at least one subburst area in the burst area allocated to the first terminal supporting the C-MIMO selected based on the terminal information, in which the first terminal and the other terminal supporting the C-MIMO are identical. Message transmitting means for transmitting a burst assignment message for use.

On the other hand, a terminal in a Collaborate MIMO (hereinafter referred to as C-MIMO) wireless communication system of one embodiment of the present invention may have the same uplink subburst region as a separate C-MIMO capable terminal from a base station. Receiving means for receiving an assigning message; And transmitting means for transmitting pilots and data of a pilot pattern different from the separate C-MIMO capable terminal by using the subburst region according to the message.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and preferred embodiments. For reference, in the following description, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention are omitted.

FIG. 2 shows an uplink collaborative MIMO system, and an uplink collaborate MIMO performed between two mobile stations / portable subscriber stations and one base station / radio access station. Hereinafter, referred to as C-MIMO) system. In brief, the first terminal transmits through a different pilot pattern through the first transmission antenna TxAnt0 and the second terminal through the second transmission antenna TxAnt1. Then, the signals of the first and third channels transmitted from the first terminal and the signals of the second and fourth channels transmitted from the second terminal are spatially multiplexed through the same subcarriers in different pilot patterns. The base station having the first and second receiving antennas RxAnt0 and RxAnt1 receives the signals transmitted from the first terminal and the second terminal, respectively.

3 illustrates a frame structure used in a portable Internet system supporting IEEE 802.16d / e.

A portable Internet system using a TDD scheme divides one frame in time and uses it for transmission and reception. Referring to FIG. 3, one frame is divided into a downlink frame for transmitting data from a base station to a terminal and an uplink frame for transmitting data from a terminal to a base station, with TTG ( Transmit / receive transition gap and RTG (receive / transmit transition gap) are inserted. In the illustrated example, the downlink frame includes at least one of a preamble section, a partial usage of subchannels (PUSC) subchannel section, a full usage of subchannels (FUSC) subchannel section, and an adaptive modulation & coding (AMC) subchannel section. One uplink frame includes at least one of an uplink control symbol interval, a PUSC subchannel interval, and an AMC subchannel interval.

In particular, the present invention relates to a method of assigning a burst to an uplink frame of FIG. 3, which is assigned to an uplink map (UL-MAP) of a downlink frame and transmitted to the terminal during downlink transmission.

Hereinafter, an apparatus for supporting C-MIMO according to an embodiment of the present invention will be described. For convenience of description, this embodiment assumes an OFDM / OFDMA based 2x2 MIMO system as an example, and assumes that each terminal is capable of C-MIMO.

4 is a block diagram showing a base station (ie, a transmitting device) for supporting C-MIMO according to an embodiment of the present invention.

As shown in FIG. 4, the base station includes an interface 110, a band signal processor 120, a transmitter 130, a receiver 160, a scheduler 150, and an antenna 140. The base station supports TDD and may be divided into a reception path and a transmission path.

In the reception path, the receiver 160 receives one or more radio signals transmitted by the terminals through the antenna 140 and converts them into baseband signals. For example, the receiver 160 removes and amplifies noise from the above-described signal for data reception of the base station, down-converts the amplified signal to a baseband signal, and digitizes the down-converted baseband signal. The band signal processor 120 extracts information or data bits from the digitized signal to perform demodulation, decoding, and error correction processes. The received information is transmitted to the adjacent wired / wireless network via the interface 110 or transmitted to other terminals serviced by the base station.

In the transmission path, the interface 110 receives voice, data, or control information from a control station or a wireless network, and the band signal processor 120 encodes voice, data, or control information and outputs the encoded information to the transmitter 130. do. The transmitter 130 modulates the encoded voice, data, or control information into a carrier signal having a desired transmission frequency or frequencies, amplifies the modulated carrier signal to a level suitable for transmission, and propagates to the air through the antenna 140. do.

On the other hand, the scheduler 150 controls the operation of the reception path and the transmission path and each component, the configuration for a C-MIMO system according to an embodiment of the present invention is shown in FIG.

FIG. 5 is a diagram illustrating the scheduler of FIG. 4. As shown in FIG. 5A, the C-MIMO searching unit 151, the parameter obtaining unit 155, and the C-MIMO alignment unit 152 are illustrated. ), A C-MIMO group unit 153, and a resource allocating unit 154.

The cooperative multi-input / output search unit 151 refers to basic capacity such as physical parameter information and bandwidth allocation information provided from terminals in a system environment in which SISO and MIMO are mixed. Search for terminals capable of C-MIMO.

The parameter obtaining unit 155 obtains information on terminals applying the C-MIMO found by the cooperative multiple input / output searching unit 151. The information of the terminals may be divided into location information of the terminals and channel quality information of the terminals. The channel quality information of the terminals may include ranging channel information of the terminals, uplink sounding channel information of the terminals, and the terminal. For example, parameters such as CINR information through the CQI channel, power allocation information of the terminal, MCS level information of the terminal, and the like.

The C-MIMO sorting unit 152 sorts the terminals using the above-described parameters or a combination of parameters. For example, when sorting using the location information of the terminal, the base station sorts the terminals in the nearest position, and when sorting using the CINR information of the terminal, the interference is low and the signal state is good through the CQI channel of the terminal. When sorting by the higher terminal order and using the allocated power of the terminal, the terminals are sorted in the order of the higher power allocation of the terminal. At this time, it is also possible to align the terminal in consideration of at least two parameters.

The C-MIMO group unit 153 groups using the terminals arranged through the C-MIMO aligning unit 152, and the grouping in the present embodiment is a case of a 2x2 C-MIMO system for convenience of description. Take pairing as an example. As illustrated in FIG. 5B, the C-MIMO group unit 153 selects a terminal pair having the largest amount of bursts among the grouped terminals using the burst allocation information for each terminal fed back. The terminal pair selection unit 153a may further include a C-MIMO regroup unit 153b for regrouping each of the other terminals except for the grouped terminals and the other terminals except for the grouped terminals.

The above-described grouping method will be described in more detail with reference to FIGS. 6 and 7.

FIG. 6 is a diagram illustrating a method for grouping C-MIMO terminals in a base station according to an embodiment of the present invention, wherein the terminal having the remaining priority based on the terminal having the highest priority among the sorted orders in the C-MIMO sorting unit 152 is illustrated. Group with them. That is, the above-mentioned one highest priority terminal and the plurality of remaining terminals are grouped.

Referring to FIG. 6, if the C-MIMO sorting unit 152 sorts in order of a, b, c, and d terminals based on the above-described parameters or a combination of these parameters, the C-MIMO grouping unit 153 ) Groups terminal a and terminal b, terminal a and terminal c, terminal a and terminal d, respectively. Such grouping is possible even with five terminals. That is, it can be seen that grouping is possible for odd terminals for C-MIMO. Therefore, there is an advantage that the size of the uplink map is reduced.

In addition, the C-MIMO group unit 153 selects a terminal pair to which the largest amount of bursts are allocated based on the burst allocation information fed back from the resource allocation unit 154, and then groups the terminal pairs in the next frame, Regroup using terminals. For example, if the largest amount of bursts are allocated to terminal a and terminal c in the current frame, group a and terminal c in the next frame and use terminal b or terminal d except this pair of terminals. .., z Regroup with terminals.

At this time, in the present specification, for convenience of description, the C-MIMO group unit 153 is described as selecting and grouping a terminal pair assigned the largest amount of bursts in a subsequent frame, but the C-MIMO group unit 153 Note that we may choose to group the terminal pairs with the highest burst allocation (i.e. the best performance) by continually observing a few frames rather than the next.

FIG. 7 is a diagram illustrating a method for grouping C-MIMO terminals in a base station according to another embodiment of the present invention, and shows a method of grouping an optimal terminal pair for C-MIMO described above.

Referring to FIG. 7, if the C-MIMO sorting unit 152 sorts in order of a, b, c, and d terminals based on the parameters or a combination of these parameters, the C-MIMO grouping unit 153 may be configured as follows. Group a terminal and terminal b, terminal a and terminal c, terminal a and terminal d in the current frame. The resource allocator 154 allocates a different amount of bursts according to each terminal pair for the grouped terminal pairs, and feeds the burst allocation information back to the C-MIMO group unit 153 to reconstruct the terminal of the next frame. Make a reference to the grouping. Accordingly, in the next frame, the C-MIMO group unit 131 selects a terminal pair to which the largest amount of bursts are allocated based on the fed back burst allocation information, and then regroups the remaining terminals except for the selected terminal pair.

In the example shown, if the resource allocator 154 allocates the largest amount of bursts to terminal a and terminal c in the current frame, group terminal a and terminal c in the next frame and then group other terminals. In order to regroup the other terminals on the basis of terminal b in the same manner as in FIG. 6, and further group the remaining terminals on the basis of the d terminal in the same manner as in FIG. 6.

Meanwhile, the resource allocator 154 allocates resources for the terminals grouped by the C-MIMO group unit 153, that is, designates an area for allocating bursts of the grouped terminals, and assigns pilot patterns to the respective terminals. After allocating this, an uplink map message is created based on this. In addition, the resource allocator 154 includes a feedback unit 154d for feeding back the above-mentioned burst allocation information to the C-MIMO group unit 153, whereby the C-MIMO group unit 153 makes C the next frame transmission. -Make a reference to regroup MIMO terminals.

In this case, the above-described burst allocation may be performed based on the location of the terminals in the cell, or may be performed based on the channel quality of the terminals.

For example, when assigning bursts based on location, the same amount of burst is allocated to terminals having the same distance from the base station. On the other hand, when the distance between the base station and the terminal is different, a relatively large amount of burst is allocated to a terminal that is close to the base station, and a relatively small amount of burst is allocated to a terminal that is far from the base station. It can also increase utilization.

On the other hand, when the burst is allocated based on channel quality, a relatively large amount of burst is allocated to terminal pairs having good channel quality, and a relatively small amount of burst is allocated to terminal pairs having poor channel quality. The resource allocator 154 includes a burst allocator 154a for allocating bursts of respective terminals and a pilot pattern allocator for differently assigning pilot patterns of the respective terminals, as shown in FIG. 154b) and map information element recording means 154c for recording the above-mentioned burst assignment information and pilot pattern assignment information in an uplink map.

Alternatively, the resource allocator 154 may include a first burst allocator (not shown) for allocating a burst for the first terminal pair, and a burst for dividing the burst area for the second terminal into a plurality of subburst areas. A splitter (not shown), a second burst allocator (not shown) for allocating bursts for a second plurality of terminals to at least one subburst region, and different terminals for the terminals of the first terminal pair A pilot pattern allocator 154b for allocating a pilot pattern and assigning different pilot patterns for the second terminal and the second plurality of terminals, the first pair of terminals, the second terminal, and the second plurality of terminals; Map information element recording means (154c) for recording the burst allocation information and the pilot pattern allocation information for the terminals of the uplink map (UL-MAP).

Hereinafter, the resource allocator 154 described above will be described in more detail with reference to FIGS. 8 to 10.

8 is a diagram illustrating a burst allocation method according to an embodiment of the present invention, in which a base station designates a burst region in an OFDM / OFDMA uplink frame, and a part of the designated burst region is a subburst (UL subburst ab, UL subburst) ac, UL subburst ad) region, and then shows a method of creating an uplink map message to allocate bursts of terminals to the divided subburst region.

Referring to FIG. 8, a preamble, a frame control header (FCH), a downlink map (DL-MAP), an uplink map (UL-MAP), and a downlink burst (DL Burst) are configured in a downlink period. In the uplink period, ranging, ranging, ACK and CQI, and UL bursts. Here, the preamble is used to provide time and frequency synchronization and cell information to users, the FCH contains information for decoding the downlink map (DL-MAP), the downlink map (DL-MAP) is a base station Downlink bursts (DL Bursts) to be transmitted include information on which terminal data is located and in which region in the frame. Meanwhile, the uplink map UL-MAP includes information on uplink bursts transmitted by the terminals. Accordingly, the base station transmits the resource allocation information for the terminal pairs to the respective terminals during the downlink transmission period on the uplink map (UL-MAP) of the above-described OFDM / OFDMA frame, each terminal is assigned to the burst The data is allocated to the base station during the uplink transmission period.

In the illustrated example, the base station assigns information for allocating bursts of terminals a and b to the subburst area ab (UL subburst ab), and assigns bursts of terminals a and c to the subburst area ac (UL subburst ac). An uplink map (UL-MAP) message is created that includes information instructing to assign and information indicating to allocate bursts of terminals a and d to the subburst area ad (UL subburst ad). By using such a subburst region, the base station may increase the utilization of resources by differently allocating the burst amounts of the C-MIMO capable terminals.

9 is a diagram illustrating a pilot pattern applied to an uplink PUSC mode in an OFDM / OFDMA based 2x2 C-MIMO system according to an embodiment of the present invention. A pilot pattern transmitted by the antenna TxAnt and the antenna TxAnt of the second terminal, respectively.

Referring to FIG. 9, the antenna TxAnt of the first terminal transmits pilot and data in the pattern (pilot pattern A) shown in FIG. 9 (a), and the antenna TxAnt of the second terminal is illustrated in FIG. 9 (b). The pilot and data are transmitted in the pattern shown in Fig. 9 (pilot pattern B). Then, the first reception antenna RxAnt0 of the base station receives the first and second reception signals (that is, the reception signals of the first channel and the second channel) through the first and second channels H00 and H01, respectively. The second reception antenna RxAnt1 receives the third and fourth reception signals (that is, the reception signals of the third channel and the fourth channel) through the third and fourth channels H10 and H11, respectively. And all signals transmitted from the second terminals (uplink frame).

In the example of FIG. 8 again, the resource allocator 154 allocates pilot pattern A for terminal a and assigns pilot pattern B for terminals b, c, and d. Accordingly, the terminal pair is spatially multiplexed on the same subcarrier during data transmission. Of course, the base station may alternately allocate pilot patterns A and B. At this time, the above-described series of burst allocation information and pilot pattern allocation information for each terminal are recorded in the map information element.

The above-described map information element may be an example of MIMO_UL_Basic_IE described in Table 1 below.

TABLE 1

The uplink interval usage code (UIUC) is used to define an uplink access type and a burst type associated with the access. When the value of the UIUC in the uplink map is 15, it corresponds to an extended UIUC (current UIUC). Element [MIMO_UL_Basic_IE ()] means conveying special information (ie MIMO). The MIMO_UL_Basic_IE () includes a data area, a CID for each terminal, and pilot pattern allocation information for C-MIMO. In Table 1, 'Num_Assign' indicates the burst allocation number, and allocates the CID of the corresponding terminal and the pilot pattern of the corresponding terminal by the above-mentioned burst allocation number through the 'for' syntax.

FIG. 10 is a diagram illustrating a burst allocation method according to another embodiment of the present invention, in which a burst allocation method for a terminal pair determined in a current frame (eg, a terminal and c terminal in FIG. 8) and terminals regrouped in a next frame are illustrated in FIG. A burst allocation method for a pair is shown.

Referring to FIG. 10, the resource allocator 154 may include a C-MIMO group unit (C-MIMO group unit) for retransmitting information on the optimal pair of terminals found in the current frame through the method shown in FIG. 8 and the remaining terminals. 153, and assigns a burst based on this information.

In the example shown, the resource allocator 154 is allocated the most amount of bursts of the a and c terminal pairs in the current frame, so that in addition to the burst allocation for the a and c terminal pairs in the next frame, the terminal b and terminal d, terminal b And uplink map messages are created for allocating bursts for e terminals, ..., b terminals and z terminals, for example, as shown in FIG. That is, in FIG. 8, the resource allocating unit 154 assigns bursts of terminals b and d to the subburst area bd (UL subburst bd), and the bursts of terminals b and e to the subburst area be (UL subburst). The information allocated to be) and the information for allocating the bursts for the remaining terminals in the subburst region in the same way are included in the UL-MAP message. In addition, the resource allocator 154 includes information for allocating pilot pattern A to terminal b and information for allocating pilot pattern B to terminals d, e, f, ..., z in the uplink map message. Let's do it. Of course, you can also assign the pilot pattern in reverse. In the same manner, the uplink map message can be created to allocate the burst to the terminal d in the same manner as described above.

Each terminal loads data in a subburst region allocated to it by referring to an uplink map on which such resource allocation information is recorded, and then uses the same subcarrier for successive OFDMA symbols to transmit the aforementioned data to each base station. send. Accordingly, the base station may receive an uplink frame transmitted through the same subcarrier for each terminal, and may restore the data by estimating a corresponding channel using pilots included in at least one tile.

Hereinafter, a method for supporting C-MIMO according to the present invention will be described with reference to the above-described grouping method and resource allocation method. For reference, a detailed process or principle of operation of the method for supporting C-MIMO according to the present invention may refer to the description of the apparatus for supporting the C-MIMO described above, and thus, redundant description thereof will be omitted. The following briefly describes the steps occurring.

11 is a diagram illustrating a method for supporting C-MIMO according to an embodiment of the present invention.

Referring to FIG. 11, first, each of the terminals informs the base station of its capability in an SSBC Basic Capability Request (SBC-REQ) message, and the base station determines the basic capabilities of the terminals and the base station to determine the SBC-RSP ( In response to the SS Basic Capability Response) message (S310).

Subsequently, upon receiving the SBC-RSP message from each terminal, the base station registers the corresponding terminal (S320). Here, registration means that the base station connects the terminals to the network and receives the additional management CID from the terminals and switches the terminals to a manageable state. To this end, the terminals transmit a REG-REQ message to the base station, and the base station responds using the REG-RSP message. In this case, the REG-REQ message includes the above-described additional management CID, and the REQ-RSP message includes a right for the terminal to transmit traffic to the communication network.

Next, the base station performs scheduling for data transmission to the terminals (S330). Here, scheduling is to group terminals for C-MIMO, and to determine resources to be allocated to the grouped terminals, and the above-described determination of resources designates a burst area for each terminal in an uplink frame, and sets a pilot pattern. This means creating an uplink map message for allocation. Such scheduling has been described with reference to FIGS. 6 to 10 described above, and will be briefly described with reference to FIG. 12.

Subsequently, the base station loads the resource allocation information determined for each terminal according to the aforementioned scheduling on the uplink map and transmits the information to the terminals during the downlink transmission (S340). That is, in the burst area allocated to one terminal supporting C-MIMO selected based on the terminal information, at least one subburst area is equally used by the one terminal and the other terminal supporting the C-MIMO. Transmits an uplink map message. At this time, the uplink map message specifies that different pilot patterns are allocated to the one terminal and the other terminal.

Each of the terminals receives the frame, decodes the data into respective data, and allocates the data synchronized to the uplink burst as indicated by the uplink map during uplink transmission, and transmits the data to the base station (S350-S360). ). In this case, the grouped terminals transmit data with pilots of different pilot patterns.

12 is a flowchart illustrating a scheduling method for supporting C-MIMO according to an embodiment of the present invention.

Referring to FIG. 12, first, C-MIMO-enabled terminals are searched for in a system environment in which SISO and MIMO are mixed with reference to basic capacities exchanged between terminals and a base station (S331).

Subsequently, parameters for the discovered terminals are obtained (S332). This parameter may be, for example, the location of the terminal, a carrier to interference and noise ratio (CINR) through the CQI channel of the terminal, and the allocated power of the terminal.

Next, the terminal is aligned using the above-described parameters or a combination of parameters (S333). For example, when sorting using the location information of the terminal, the terminals are sorted in order of the nearest terminals, and when the terminal is sorted using the CINR information of the terminal, the terminal has a low interference and a good signal state through the CQI channel of the terminal. In order of sorting and using the allocated power of the terminals, the terminals are arranged in the order of the largest power allocation of the terminals. In this case, it is also possible to arrange the terminals in consideration of at least two parameters.

Subsequently, the sorted terminals are grouped (S334). That is, as described with reference to FIG. 6, based on the terminal having the highest priority among the aligned terminals, the terminal is grouped with the terminals of the remaining priority. Then, as described with reference to FIG. 7, the terminal pairs assigned the most bursts are grouped in the next frame based on the feedback burst allocation information, and regrouped again using the remaining terminals.

In operation S335, resources for the grouped terminals are allocated. That is, as described in FIG. 8, burst allocation information for the grouped terminal pairs is included in the UL map. In this case, the burst area to be allocated to any one of the terminal pairs described above is divided into a plurality of subburst areas, and the bursts of the other terminals except for the terminal are divided into at least one of the plurality of subburst areas. After assigning to the subburst region, a different pilot pattern is allocated to each terminal of the terminal pair. In addition, an optimal terminal pair searched through the method shown in FIG. 8 in the current frame and information of regrouping the remaining terminals are received for the next frame transmission, and based on the information, the resource as described in FIG. 9 and FIG. To be assigned.

Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art to which the present invention pertains can implement the present invention in other specific forms without changing the technical spirit or essential features, The examples are to be understood in all respects as illustrative and not restrictive. For example, in the present invention, the terminal has been an example of using one antenna, it will be easily understood that the technical idea of the present invention can be equally applied by selectively using an antenna even when using a plurality of terminals.

In addition, the scope of the present invention is specified by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention. Should be interpreted as

According to the present invention, there is an effect of enabling more efficient use of resources to perform C-MIMO.

In addition, according to the present invention, by efficiently allocating resources to grouped terminals as described above in a C-MIMO structured wireless communication system, it is possible to obtain improved system performance and maximize utilization of limited resources. It works.

Further, according to the present invention, by grouping a plurality of terminals and one of the terminals that can cooperate in a wireless communication system of the C-MIMO structure, it is possible to quickly search for the most suitable terminal pair for C-MIMO, and also odd Groups can also be grouped, and the map size can be reduced.

Claims (26)

As a method for supporting C-MIMO (Collaborative MIMO) in a wireless communication system, Arranging the plurality of C-MIMO capable terminals using location information or channel quality information; And Transmitting a message including burst allocation information configured to pair each of at least two terminals selected except for the top terminal and the top terminal in a burst area allocated to the top terminal among the sorted terminals; Method for supporting C-MIMO, characterized in that it comprises a. The method of claim 1, wherein the burst allocation information, And information indicating at least two subburst areas of the burst areas allocated to the highest priority terminal. The method of claim 1 or 2, wherein the message, And pilot pattern information for allowing the highest priority terminal and the at least two terminals to have different pilot patterns from each other. The method of claim 3, wherein the message, Method for supporting C-MIMO, characterized in that the uplink map (UL-MAP). An uplink scheduling method in a C-MIMO (Collaborative MIMO) wireless communication system, (a) at least two selected C-MIMO capable terminals according to a channel state in the current frame, and excluding the first priority terminal and the first priority terminal within a burst allocation region of a first priority terminal; Transmitting first burst allocation information configured for pairing of terminals of each of the plurality of terminals; And (b) In a next frame, selecting first pair terminals to which the highest amount of bursts are allocated among the paired pair terminals, burst allocation information for the first pair terminals, and second except the first pair terminals. A second burst allocation including burst allocation information configured to select a first terminal and to configure at least two terminals selected except for the second priority terminal and the second priority terminal in a burst allocation region of the second priority terminal; And transmitting the information. The method of claim 5, wherein the first burst allocation information, And at least one subburst region of the burst allocation region of the first priority terminal. The method of claim 5, wherein step (a) comprises: And transmitting information for allocating different pilot patterns to at least two terminals selected except for the first priority terminal and the first priority terminal. The method according to any one of claims 5 to 7, wherein the second burst allocation information, And at least one subburst region of the burst allocation region of the second preferred terminal. The method of claim 8, wherein step (b) And transmitting information for allocating different pilot patterns to at least two terminals selected except for the second priority terminal and the second priority terminal. The method of claim 8, wherein the first burst allocation information and the second burst allocation information, Scheduling method, characterized in that each is transmitted using an uplink map (UL-MAP) message of the frame. Receiving registration messages containing terminal information from a plurality of terminals, respectively; And The first terminal and the second terminal supporting the C-MIMO share a first sub-burst region in the burst area allocated to the first terminal supporting the C-MIMO selected based on the terminal information. And transmitting an uplink map message configured to share a second subburst region between the first terminal and a third terminal supporting the C-MIMO. . The method of claim 11, wherein the uplink map message, Method for supporting C-MIMO characterized in that the transmission to the plurality of terminals during the downlink transmission interval. The method of claim 11 or 12, wherein the uplink map message, C-MIMO, wherein the first terminal and the second terminal are assigned different pilot patterns, and the first terminal and the third terminal are assigned different pilot patterns. How to support. A first terminal supporting Collaborative MIMO (C-MIMO) supports information about a first subburst region of an uplink burst region shared by a second terminal supporting C-MIMO and a C-MIMO from a base station Receiving a message including information on a second subburst region of the uplink burst region shared by a third terminal; And Transmitting, by the first terminal, data and pilot using the first subburst region and the second subburst region according to the message, And the message indicates information indicating a first pilot pattern to the first terminal and indicates a second pilot pattern to the second terminal and the third terminal. The method of claim 14, wherein the first subburst region and the second subburst region, And a part of a two-dimensional burst region allocated to the first terminal in frequency and time. An uplink scheduling apparatus in a C-MIMO (Collaborative MIMO) wireless communication system, A C-MIMO group unit for pairing at least two terminals with the selected first terminal based on the information on the C-MIMO supporting terminals; And And a resource allocating unit for allocating a first subburst region in the uplink burst region for the first terminal to the first pair terminals in common and a second subburst region to the second pair terminals in common. A scheduling apparatus. The method of claim 16, wherein the resource allocation unit, A burst divider for dividing the burst allocation region of the first terminal into a plurality of subburst regions; A burst allocator for allocating the first pair of terminals to the first subburst region and allocating the second pair terminals to the second subburst region; A pilot pattern allocator configured to differently assign pilot patterns to pair terminals of each of the first pair terminals and the second pair terminals; And And a map information element recording unit for recording the pilot pattern allocation information and the burst allocation information in an uplink map (UL-MAP). The method of claim 16, wherein the resource allocation unit, And a feedback unit for feeding back the burst allocation information for the first terminal and the at least two terminals to the C-MIMO group unit. The method of claim 18, wherein the C-MIMO group unit, A terminal group selector which selects pair terminals occupying the largest burst area among the pair terminals by using the burst allocation information for the fed back first terminal and the at least two terminals; And And a C-MIMO regrouping unit for selecting a second terminal among the terminals other than the selected pair terminals and repairing the second terminal and at least two terminals except the second terminal. . delete As a base station in a C-MIMO (Collaborative MIMO) wireless communication system, A receiving unit for receiving a registration message including terminal information from a plurality of terminals, respectively; And In the burst area allocated to the first terminal supporting the C-MIMO selected based on the terminal information, the first terminal and the second terminal supporting the C-MIMO share a first subburst area and the first terminal. And a message transmitter configured to transmit a burst allocation message configured to share a second subburst region between a terminal and a third terminal supporting the C-MIMO. The method of claim 21, wherein the message transmission unit, The base station, characterized in that for designating different pilot patterns to the first terminal and the second terminal, and transmits the pilot pattern information for designating different pilot patterns to the first terminal and the third terminal. A terminal in a Collaborative MIMO (C-MIMO) wireless communication system, From the base station, the C-MIMO supporting terminal and the first other terminal share the first subburst region of the uplink burst region, and the second other terminal supporting the C-MIMO and the second terminal of the uplink burst region A receiving unit for receiving a message configured to share the subburst area; And A transmission unit for transmitting data and pilot using the first subburst region and the second subburst region according to the message, And the message indicates information indicating the first pilot type to the terminal and indicating the second pilot type to the first and second other terminals. The method of claim 23, wherein the first subburst region and the second subburst region, And a part of a two-dimensional burst region allocated to the terminal in frequency and time. As a method of performing Collaborative MIMO (C-MIMO) in a wireless communication system, The terminal uses the first other terminal supporting C-MIMO from the base station and the first subburst region of the uplink burst region of the terminal in common and the second other terminal supporting the C-MIMO and the first uplink burst region of the terminal. Receiving a message configured to commonly use two subburst regions; And The terminal transmits data and pilots of the terminal to the base station using the first subburst region for pairing with the first other terminal and the second subburst region for pairing with the second other terminal. Sending a step, C in the first subburst region and the second subburst region, the pilot type of the terminal is a first pilot type and the pilot type of the first other terminal and the second other terminal is a second pilot type. -How to do MIMO. delete

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