KR20090098593A - Apparatus and method for pairing terminals in ul mimo system - Google Patents

Abstract

An apparatus and a method for pairing terminals in a UL MIMO system are provided to increase service quality by pairing the terminals that are in good state based on a CINR(Carrier to interference and Noise Ratio). A terminal arranging unit(230) sequentially arranges the terminals that enable C-MIMO(Collaborative MIMO), and a terminal pairing unit(250) pairs the terminals based on the arranged order. A channel correlation calculator(240) calculates the channel correlation for the combination of a pair of terminals that enable the C-MIMO. The terminal pairing unit pairs first and second ranking terminals above all, and performs terminal pairing for every period.

Description

Apparatus and method for pairing terminals in UL MIMO system}

The present invention relates to a device and method for pairing (pairing) terminals in a UL MIMO system, and more particularly, MIMO wireless communication that supports OFDM / OFDMA schemes following IEEE 802.16d / e, Wibro, WiMAX, etc. An apparatus and method for efficiently pairing terminals in uplink (UL) burst transmission in a system.

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 supporting mobile Internet service in a mobile environment is being actively researched. Multiple input multiple output (MIMO) systems are emerging to support Internet services.

1 is a diagram illustrating an outline of a general SISO system and a MIMO system.

As shown in FIG. 1A, a single input single output (SISO) system uses a single antenna (TxAnt, RxAnt) on a transmitting side and a receiving side, for example, a terminal having one antenna (TxAnt) and A signal is transmitted and received through one channel H formed between a base station having one antenna RxAnt.

MIMO (Multiple Input Multiple Output) system is a technology that transmits data through multiple paths by increasing the number of antennas of a terminal and a base station, and can improve transmission efficiency through space-time diversity and spatial multiplexing on the transmitting side, and each path on the receiving side. The interference can be reduced by detecting the received signal. For example, FIG. 1B illustrates a 2x2 MIMO system including a base station having two antennas TxAnt0 and TxAnt1 and a base station having two antennas RxAnt0 and RxAnt1. Four channels, that is, the first channel H00, the second channel H01, and the third channel between the first and second antennas TxAnt0 and TxAnt1 of the base station and the first and second antennas RxAnt0 and RxAnt1 of the base station. 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 between the transceivers is improved compared to the SISO system. That is, in a multipath rich environment, multiple orthogonal channels can be formed between the 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. As a result, higher spectral efficiency than the SISO system is achieved.

However, in the uplink of the 2 × 2 MIMO system, as described above, since two antennas are required for each terminal, power loss of the terminal is increased and hardware complexity increases. Therefore, C-MIMO (Collaborative MIMO) has been studied to increase the transmission rate like MIMO using a terminal having a simpler hardware structure and a single antenna, and more efficient methods for performing such C-MIMO are required. It is becoming.

The present invention was devised to solve the above-described needs, and an object of the present invention is to provide an apparatus and method for efficiently pairing a plurality of terminals when performing C-MIMO.

Another object of the present invention is to provide an apparatus and method for terminal pairing in a UL MIMO system that can improve service quality by pairing terminals having good channel conditions using CINR of the terminal.

It is still another object of the present invention to provide a terminal pairing apparatus and method for performing a terminal pairing algorithm at a predetermined cycle and selecting C-MIMO or SIMO according to a result of comparing the data rate of C-MIMO and the data rate of SIMO.

Yet another object of the present invention is to use UL CIMO and channel correlation to pair UEs, and UL MIMO capable of improving overall throughput by allocating more resources for a terminal pair having low channel correlation. An apparatus and method for terminal pairing in a system are provided.

For this purpose, an apparatus for pairing terminals in an UL MIMO system of one embodiment of the present invention includes a terminal alignment unit for arranging C-MIMO (Collaborative MIMO) capable terminals in CINR order; And a terminal pairing unit configured to pair the terminals based on the sorted order.

Preferably, the terminal pairing apparatus further comprises a channel correlation calculator for calculating a channel correlation for the combination of the C-MIMO (Collaborative MIMO) capable terminal pair, the terminal pairing unit arranged in the highest priority or the lowest priority The terminal pair having the lowest channel correlation among pairs of terminal pairs consisting of the terminal and the other terminals is preferentially paired.

On the other hand, in the UL MIMO system of one embodiment of the present invention, a method for pairing a terminal comprises: a) arranging C-MIMO (Collaborative MIMO) capable terminals in CINR order; And b) pairing the terminals based on the sorted order.

In addition, a method of pairing UEs in a UL MIMO system according to another aspect of the present invention includes: a) arranging C-MIMO (Collaborative MIMO) capable terminals in CINR order; b) calculating channel correlations for the highest priority terminal and the remaining terminals among the aligned terminals, respectively; And c) preferentially pairing the terminal pair having the lowest channel correlation.

In addition, a method of pairing UEs in a UL MIMO system according to another aspect of the present invention may include: a) selecting one UE randomly among C-MIMO (Collaborative MIMO) capable terminals; b) calculating a CINR difference between the selected terminal and the remaining terminals, respectively; And c) first pairing the selected terminal with a terminal having a smallest CINR difference.

In addition, a method of pairing UEs in a UL MIMO system according to another aspect of the present invention includes a) calculating a CINR of a SIMO (Single Input Multiple Output) for UEs capable of Collaborative MIMO (C-MIMO); b) when the CINR of the SIMO is greater than or equal to a preset threshold, pairing the terminals to calculate the CINR of the C-MIMO; c) determining a data rate corresponding to the CINR of the C-MIMO; And d) determining, for the paired terminals, C-MIMO or SIMO by comparing the data rate of C-MIMO with the data rate of SIMO.

Accordingly, the present invention has the effect of improving the quality of service by pairing terminals having good channel conditions using CINR.

In addition, the present invention pairs UEs using CINR and channel correlation (orthogonal, eigen ratio, etc.) and allocates more resources to UE pairs having low channel correlation to maximize limited resources. It has the effect of improving system performance by utilizing.

In addition, the present invention has the effect of increasing the data rate by performing the terminal pairing algorithm at a predetermined period, and determines the C-MIMO or SIMO according to the comparison result of the data rate of the C-MIMO and the data rate of the SIMO.

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

FIG. 2 illustrates an UL (Multilink Multiple Output Multiple Output) system, in particular 2 × 2 C consisting of two mobile stations (Mobile Station / Portable Subscriber Station) and one base station (Base Station / Radio Access Station). -Collaborative MIMO system is illustrated.

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. For reference, FIG. 3 illustrates pilot patterns transmitted by the first transmit antenna TxAnt0 and the second transmit antenna TxAnt1 in the UL PUSC mode of the 2 × 2 C-MIMO system, respectively. Then, the signals of the first channel H00 and the third channel H10 transmitted from the first terminal and the signals of the second channel H01 and the fourth channel H11 transmitted from the second terminal are different from each other. As a result, a base station having spatial multiplexing and transmission through the same subcarrier and having first and second reception antennas RxAnt0 and RxAnt1 receives both signals transmitted from the first terminal and the second terminal, respectively.

In this regard, FIG. 4 illustrates an example of a resource allocation scheme for the case of non-MIMO (FIG. 4A) and the case of C-MIMO (FIG. 4B). Referring to FIG. 4, the same subchannel is used for C-MIMO. It can be seen that by transmitting a plurality of bursts (UL Burst # 1 and UL Burst # 2 of FIG. 4B), more data can be transmitted with limited resources.

5 illustrates a configuration of a base station to which a terminal pairing device according to the present invention can be applied.

As shown in FIG. 5, the base station includes an interface 110, a band signal processor 120, a transmitter 130, a receiver 160, a scheduler 150, an antenna 140, and the like. The illustrated base station supports TDD, and also includes 2 antennas to support 2x2 MIMO by transmitting and receiving signals through respective transmission paths and reception paths.

In the reception path, the receiver 160 receives one or more radio signals transmitted by the terminals through the antenna 140 and converts the signal into a baseband signal. For example, the receiver 160 removes and amplifies noise from the above-described signal for data reception by the base station, down converts the amplified signal into 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.

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 the voice, data, or control information and transmits the same 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, amplifies the modulated carrier signal to a level suitable for transmission, and propagates to the air through the antenna 140.

Meanwhile, the scheduler 150 performs scheduling by allocating DL_MAP, UL_MAP, downlink burst, uplink burst, and the like to a frame formed of a symbol and a subchannel for transmission and reception with a terminal. At this time, when the C-MIMO is applied, the C-MIMO capable terminals are paired. Therefore, the terminal pairing device according to the present invention may be implemented by the scheduler itself or a part thereof, or may be implemented as a separate device.

6 illustrates a process of performing a UL MIMO by a base station and a terminal in accordance with the present invention.

In brief, the UE informs the base station of its capability through the SS Basic Capability Request (SBC-REQ) message, and the base station determines the basic capability between the terminals and the base station in consideration of the SBC-REQ message. The response is made through an SS Basic Capability Response (RSP) message (S610). Subsequently, the terminal transmits a REG-REQ (Registration Request) message to the base station, and the base station responds with a REG-RSP (Registration Response) message, thereby performing registration (S620). In addition, the base station performs scheduling for data transmission and reception with the terminals (S630). At this time, the scheduler selects and pairs C-MIMO capable terminals and allocates resources by designating a burst area of the paired terminals in an uplink frame. When the UL_MAP is created by allocating the resources, the base station includes the UL_MAP in the downlink frame and transmits the UL_MAP to the terminal (S640). After decoding the terminal (S650), the base station transmits data to the base station in a designated uplink burst (S650). S660). Here, the paired terminal pairs transmit data in different pilot patterns in the same burst.

Hereinafter, an apparatus and method for pairing a terminal in a UL MIMO system according to the present invention will be described with reference to FIGS. 7 to 11. For convenience of description, this embodiment assumes an OFDM / OFDMA based 2x2 C-MIMO system as an example, and assumes that each terminal is capable of C-MIMO.

7 is a block diagram of a terminal pairing device according to an embodiment of the present invention. As shown, the terminal pairing apparatus 200 according to the present invention is the terminal search unit 210, the terminal information collection unit 220, the terminal alignment unit 230, the channel correlation calculator 240, the terminal pairing unit 250 and the like.

The terminal search unit 210 refers to basic capacity such as physical parameter information and bandwidth allocation information provided from the terminals and refers to C- in a system environment in which SISO and MIMO are mixed. Search for terminals applicable to MIMO.

The terminal information collecting unit 220 obtains information on C-MIMO applicable terminals found by the terminal searching unit 210. The terminal information may include location information of the terminal and channel quality information of the terminal, and the channel quality information of the terminal may include ranging channel information, uplink sounding channel information, and CQI (Channel). Examples include parameters such as carrier to interference and noise ratio (CINR) information, power allocation information, and modulation coding scheme (MCS) level information through a Quality Indicator (CN) channel. In particular, in connection with the present invention, the terminal information collection unit 220 obtains CINR information when each terminal is implemented with a single input multiple output (SIMO) or C-MIMO. As the CINR information, PCI CI (Physical CINR) information and ECINR (Effective CINR) information can be used. Here, the PCINR can be used, for example, CINR obtained in each subcarrier unit, and the ECINR is obtained in burst unit, for example. CINR (ie, averaged PCINR of all subcarriers included in the burst) can be used.

The terminal sorter 230 sorts the terminals using the parameter or a combination of parameters. For example, the position information of the terminal is used or the terminal is arranged in order of the terminal close to the base station by calculation, or the channel state of the channel is sorted using the CINR information of the terminal.

The channel correlation calculator 240 calculates channel correlations of the terminals using an orthogonal value, an eigen ratio, and the like between channels. The channel correlation indicates the degree to which the channel is affected due to interference between terminals, etc. It is preferable that the channel correlation is low or low in order to guarantee the performance of the C-MIMO system.

The terminal pairing unit 250 pairs the terminals based on information provided from the terminal searching unit 210, the terminal information collecting unit 220, the terminal arranging unit 230, and the channel correlation calculator 240. do. For example, it is possible to consider pairing or randomly pairing the terminals according to the sorting order. In the present invention, the terminals are paired in the following manner (algorithm) using at least one of CINR and channel correlation. .

First, the UEs are arranged in CINR order in SIMO (Single Input Multiple Output) and then paired in order.

In detail, first, CINRs are obtained for all terminals, and then terminals are sorted based on the CINRs. The pair of UEs having the largest CINR of the SIMO and the second largest UE are selected and paired. Thereafter, for the remaining terminals, a pair of UEs having the largest CINR and a UE having the second largest pair is selected and paired, and the UEs are repeatedly paired with each other.

Here, SIMO is a state in which a terminal having one antenna communicates with a base station having a plurality of antennas (that is, a state before being implemented with C-MIMO), and the CINR is calculated by, for example, Equations 1 to 3 below. Can be.

[Equation 1]

[Equation 2]

[Equation 3]

In the above equation, 'x' is a transmission signal, 'y' is a reception signal, 'P _tx ' is transmission power, 'P _loss ' is pathloss, 'h' is channel response, 'g''Is the channel gain when there is interference,' j 'is the interference index,' n 'is the noise,' σ 'is the variance, and' N _I 'is the number of interfering terminals. Represent each.

In addition, Example 1 below shows the result of pairing 10 terminals after sorting them in CINR order.

Example 1

User index: [1 2 3 4 5 6 7 8 9 10]

Sorted index: [2 4 5 9 10 3 7 6 8 1]

Paired index: {[2 4] [5 9] [10 3] [7 6] [8 1]}

Second, it gives priority to the terminal with the largest CINR and calculates channel orthogonal value with the other terminal and pairs with the lowest terminal.

In detail, first, CINRs are obtained for all terminals, and the terminals are sorted based on the CINRs. The UE having the largest CINR is selected, and channel orthogonality is calculated for each of the selected UE and the remaining UEs. The terminal with the lowest channel orthogonality is paired with the selected terminal. Thereafter, similarly, the UE with the largest CINR is selected for the remaining UEs, and the UE with the lowest channel orthogonality is paired.

Here, the channel orthogonality can be calculated using, for example, Equations 4 and 5 below.

[Equation 4]

[Equation 5]

In the above equation, 'user #' is the index of the #th user terminal, 'sc' is the subcarrier index, 'H' is the channel response, and 'H ^* ' is the conjugate of H. 'channel_gain' is channel gain, 'power' is power of the user terminal, and 'Orth_value' is an orthogonal value between two user terminals in the scth subcarrier. 'Orth' represents an orthogonality between two user terminals for all subcarriers, and 'N _sc ' represents the number of subcarriers, respectively.

And, in Example 2, after arranging CINRs for 10 UEs, the UE with the largest CINR (user index: 2) and the remaining 9 UEs (user index: 1,3,4,5,6,7, After calculating channel orthogonality for each of 8, 9, and 10, it is shown that the channel orthogonality is paired with the user terminal 8 having the lowest channel orthogonality. And, by repeating this process, all the terminals are paired.

Example 2

User index: [1 2 3 4 5 6 7 8 9 10]

Sorted index: [2 4 5 9 10 3 7 6 8 1]

2 ^nd Sorted index: [4 5 9 10 3 7 6 1] ← 1 ^st Paired index: [2 8]

Third, priority is given to the UE having the largest CINR, and the channel eigen ratio with the remaining UE is calculated to pair with the lowest UE.

In detail, first, CINRs are obtained for all terminals, and the terminals are sorted based on the CINRs. The UE having the largest CINR is selected and a channel inherent ratio for each of the selected UE and the remaining UEs is calculated. Then, the selected terminal and the terminal with the lowest channel intrinsic ratio are paired. Thereafter, similarly, the terminal with the largest CINR is selected for the remaining terminals, and the selected terminal and the terminal with the lowest channel intrinsic ratio are paired.

Here, the channel intrinsic ratio may be calculated using, for example, Equation 6 below.

[Equation 6]

In the above equation, X and Y represent a user index, and 'eigen_value' represents a channel unique value.

In addition, Example 3 is arranged after the CINR order for the ten terminals, the terminal with the largest CINR (user index: 2) and the remaining nine terminals (user index: 1,3,4,5,6,7, 8, 9, and 10 after calculating the channel inherent ratio for each, it shows that pairing with the user (9), the lowest intrinsic ratio. And, by repeating this process, all the terminals are paired.

Example 3

User index: [1 2 3 4 5 6 7 8 9 10]

Sorted index: [2 4 5 9 10 3 7 6 8 1]

2 ^nd Sorted index: [4 5 10 3 7 6 8 1] ← 1 ^st Paired index: [2 9]

Fourth, a method of randomly selecting one terminal and pairing the selected terminal with a terminal having a smallest CINR difference.

In detail, first, one terminal is randomly selected. After calculating the CINR difference between the selected UE and the remaining UEs, the UE pairs with the UE having the smallest CINR difference. Similarly, one terminal is randomly selected for the remaining terminals and paired with the terminal having the smallest CINR difference.

Example 4 below calculates a CINR difference between a randomly selected UE (user index: 2) and the remaining 9 UEs for 10 UEs, and then pairs a UE pair having the smallest CINR difference (user index: 2,5). To show

Example 4

User index: [1 2 3 4 5 6 7 8 9 10]

Computing the CINR differences of choosed user2 with other 9 users:

[| CINR_user2-CINR_user1 |, | CINR_user2-CINR_user3 |, | CINR_user2-CINR_user4 |, ..., | CINR_user2-CINR_user10 |]

2 ^nd User index: [1 3 4 6 7 8 9 10] ← 1 ^st Paired index: [2 5]

Meanwhile, after pairing the terminals using any one of the above-described schemes, the data rate of the C-MIMO and the SIMO may be compared, and the C-MIMO or the SIMO may be determined according to the result. In this case, data rate comparison may use a Modulation and Coding Scheme (MCS) level, and the pairing algorithm is preferably performed periodically every predetermined frame.

Hereinafter, a terminal pairing method according to a preferred embodiment of the present invention will be described with reference to FIGS. 8 to 11. For reference, a detailed process or operation principle of the terminal paying method according to the present invention may refer to the description of the terminal pairing apparatus described above, and thus redundant description will be omitted and briefly described.

8 is a flowchart of a terminal pairing method according to a first embodiment of the present invention.

In detail, first, the C-MIMO-capable terminals are searched for in a mixed environment of SISO and MIMO by referring to basic capacities exchanged between the terminal and the base station (S810). Subsequently, the CINR of the SIMO is calculated for the discovered terminals (S820). The terminals are arranged in the calculated CINR order (S830). Thereafter, the terminals are paired in the sorted order (S840). Finally, resources are allocated to the paired terminals (S850).

9 is a flowchart of a terminal pairing method according to a second embodiment of the present invention.

In detail, first, C-MIMO-enabled terminals are searched for in a mixed environment of SISO and MIMO with reference to basic capacity exchanged between the terminal and the base station (S910). Subsequently, the CINR of the SIMO is calculated for the discovered terminals (S920). The UE having the highest CINR is selected and the channel correlation between the selected UE and the remaining UEs is calculated (S930). The channel correlation may use the above-described channel orthogonal value, channel eigen ratio, and the like. Then, the selected terminal and the terminal having the lowest channel correlation are paired (S940). Thereafter, steps S930 and S940 are repeated for the remaining terminals to perform pairing for all terminals. Finally, resources are allocated to the paired terminals (S950).

10 is a flowchart of a terminal pairing method according to a third embodiment of the present invention.

In detail, first, C-MIMO-enabled terminals are searched for in a mixed environment of SISO and MIMO with reference to basic capacity exchanged between the terminal and the base station (S1010). Subsequently, one terminal is randomly selected with respect to the discovered terminals (S1020). After calculating the CINR difference between the randomly selected UE and the remaining terminals, the UE pairs with the UE having the smallest CINR difference (S1030). Thereafter, steps S1020 and S1030 are repeated for the remaining terminals to perform pairing for all terminals. Finally, the resource is allocated to the paired terminals (S1040).

11 is a flowchart of a terminal pairing method according to a fourth embodiment of the present invention.

In detail, first, the C-MIMO-capable terminals are searched for in a mixed environment of SISO and MIMO by referring to basic capacities exchanged between the terminal and the base station (S1110). Subsequently, the CINR of the SIMO is calculated for the discovered terminals (S1120). The CINR of SIMO calculated for each terminal is compared with a threshold (S1130), and the terminal whose CINR is smaller than the threshold is determined as SIMO (S1140). Meanwhile, a pairing algorithm for C-MIMO is performed with respect to terminals whose CINR of the SIMO is equal to or greater than the threshold (S1150). In this case, the pairing algorithm is preferably performed every predetermined period (for example, every 10 frames). The CINR of the C-MIMO is calculated for the paired UEs, and then the most suitable data rate is determined (S1160). For reference, the data rate may be determined based on the ECINR after obtaining the effective CINR (ECINR) using the physical CINR (PCINR) of the C-MIMO.

On the other hand, the CINR of the C-MIMO can be calculated by the following equations (7) to (9).

[Equation 7]

[Equation 8]

[Equation 9]

In the above equation, 'x' is a transmission signal, 'y' is a reception signal, 'P _tx ' is transmission power, 'P _loss ' is pathloss, 'h' is channel response, 'g''Is the channel gain when there is interference,' j 'is the interference index,' n 'is the noise,' σ 'is the variance, and' N _I 'is the number of interfering terminals. Represent each.

Referring back to FIG. 11, after the data rate of the C-MIMO is determined, the C-MIMO or the SIMO is determined by comparing with the data rate of the SIMO (S1170). Specifically, the data rate of the C-MIMO and the data rate of the SIMO are compared with respect to the first terminal of the paired terminal pairs, and the data rate of the C-MIMO and the data rate of the SIMO are similarly compared with respect to the remaining second terminals. Thereafter, both terminals determine the C-MIMO when the data rate of the C-MIMO is equal to or greater than the data rate of the SIMO, and otherwise determine the SIM rate. That is, when the C-MIMO is implemented, the C-MIMO is determined when there is a gain in data rate. Finally, resources are allocated to UL MAPs according to the method determined in step S1140 or S1170 (S1040). In this case, system performance may be improved by allocating more resources to a terminal pair having a higher CINR of C-MIMO.

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.

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

1 is a view for explaining the outline of a general SISO system and 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 is a diagram illustrating a pilot pattern applied to an uplink PUSC mode in a 2x2 MIMO system according to an embodiment of the present invention.

4 is a diagram illustrating a resource allocation method for the case of non-MIMO and case of C-MIMO.

5 is a diagram illustrating a configuration of a base station to which a terminal pairing device according to the present invention can be applied.

6 is a diagram illustrating a process of performing a UL MIMO by a base station and a terminal in accordance with the present invention.

7 is a block diagram of a terminal pairing device according to a preferred embodiment of the present invention.

8 to 11 are flowcharts of a terminal pairing method according to a preferred embodiment of the present invention.

Claims (18)

An apparatus for pairing terminals in an UL Uplink Multiple Input Multiple Output (MIMO) system, A terminal alignment unit for arranging C-MIMO capable terminals in a carrier to interference and noise ratio (CINR) order; And And a terminal pairing unit for pairing terminals based on the sorted order. The method of claim 1, The CINR is calculated by the following equations 1 to 3, the terminal pairing device.  [Equation 1]

[Equation 2]

[Equation 3]

('X' is the transmission signal, 'y' is the reception signal, 'P _tx ' is the transmission power, 'P _loss ' is the pathloss, 'h' is the channel response, 'g' Is channel gain in case of interference, 'j' is interference index, 'n' is noise, 'σ' is distributed, and 'N _I ' is the number of interfering terminals. Indicates.) The method according to claim 1 or 2, Further comprising a channel correlation calculator for calculating a channel correlation for the combination of the C-MIMO (Collaborative MIMO) capable terminal pair, And the terminal pairing unit preferentially pairs the terminal pair having the lowest channel correlation among the terminal pair combinations consisting of the terminal arranged in the highest priority or the lowest priority and the remaining terminals. The method of claim 3, The channel correlation may include at least one of a channel orthogonal value and a channel eigen ratio. The method of claim 4, wherein The channel orthogonal value (orthogonal value) is a terminal pairing apparatus, characterized in that calculated by the following equations (1, 2). [Equation 1]

[Equation 2]

Where 'user #' is the index of the #th user terminal, 'sc' is the subcarrier index, 'H' is the channel response, 'H ^*' is the conjugate of H, 'channel_gain' is channel gain, 'power' is power of user terminal, 'Orth_value' is orthogonal value between two user terminals in scth subcarrier, and 'Orth' is for all subcarriers Orthogonality between two user terminals, 'N _sc ' represents the number of subcarriers, respectively.) The method according to claim 1 or 2, And the terminal pairing unit preferentially pairs the highest priority terminal and the second priority terminal. The method according to claim 1 or 2, And the terminal pairing unit performs terminal pairing every predetermined period. A method for pairing terminals in an UL Uplink Multiple Input Multiple Output (MIMO) system, a) arranging Collaborative MIMO (C-MIMO) capable terminals in the order of Carrier to Interference and Noise Ratio (CINR); And b) pairing terminals based on the sorted order. The method of claim 8, Step b) is a terminal pairing method, characterized in that the first priority terminal and the second priority terminal pairing. A method for pairing terminals in an UL Uplink Multiple Input Multiple Output (MIMO) system, a) arranging Collaborative MIMO (C-MIMO) capable terminals in the order of Carrier to Interference and Noise Ratio (CINR); b) calculating channel correlations for the highest priority terminal and the remaining terminals among the aligned terminals, respectively; And c) first pairing the terminal pair having the lowest channel correlation. The method of claim 10, The channel correlation may include at least one of a channel orthogonal value and a channel eigen ratio. A method for pairing terminals in an UL Uplink Multiple Input Multiple Output (MIMO) system, a) selecting one terminal randomly among C-MIMO (Collaborative MIMO) capable terminals; b) calculating a carrier to interference and noise ratio (CINR) difference between the selected terminal and the remaining terminals; And c) first pairing the terminal with a terminal having a smallest CINR difference. A method for pairing terminals in an UL Uplink Multiple Input Multiple Output (MIMO) system, a) calculating a carrier to interference and noise ratio (CINR) of a single input multiple output (SIMO) for the C-MIMO capable terminals; b) when the CINR of the SIMO is greater than or equal to a preset threshold, pairing the terminals to calculate the CINR of the C-MIMO; c) determining a data rate corresponding to the CINR of the C-MIMO; And d) determining, for the paired terminals, a C-MIMO or a SIMO by comparing the data rate of the C-MIMO with the data rate of the SIMO. The method of claim 13, The CINR of the C-MIMO is a terminal pairing method, characterized in that calculated by the following equations (1) to (3). [Equation 1]

[Equation 2]

[Equation 3]

('X' is the transmission signal, 'y' is the reception signal, 'P _tx ' is the transmission power, 'P _loss ' is the pathloss, 'h' is the channel response, 'g' Is channel gain in case of interference, 'j' is interference index, 'n' is noise, 'σ' is distributed, and 'N _I ' is the number of interfering terminals. Indicates.) The method according to claim 13 or 14, The step d) is a terminal pairing method, characterized in that all of the paired terminal is determined as C-MIMO when the data rate of the C-MIMO is greater than the data rate of SIMO, otherwise it is determined by SIMO. The method according to claim 13 or 14, Terminal pairing method characterized in that the terminal pairing is performed in a predetermined period in step b). As a method of pairing terminals in an UL Uplink Multiple Input Multiple Output (MIMO) system, a) searching for a plurality of C-MIMO terminals having C-MIMO support capability among terminals in a cell; b) selecting a first C-MIMO terminal based on a predetermined criterion among the discovered C-MIMO terminals; And c) selecting a second C-MIMO terminal for pairing based on each channel correlation between the discovered C-MIMO terminals except for the first C-MIMO terminal and the first C-MIMO terminal. Terminal pairing method characterized in that. The method of claim 17, And the predetermined criterion is random or channel quality.

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