WO2012159303A1 - Method and apparatus for antenna group allocation in distributed antenna system - Google Patents

Abstract

The embodiments of the present invention disclose a method and an apparatus for antenna group allocation in a Distributed Antenna System (DAS). The method includes: dividing 2n antennas serving to the same cell into n antenna groups, wherein n is a natural number more than zero and there are M antenna pairing modes for the 2n antennas being divided into n antenna groups; obtaining the distance d between two antennas of each group belonging to the same antenna pairing mode; obtaining the arithmetic average value of d of the n antenna groups in each antenna pairing mode; selecting the pairing mode with the largest in the M antenna pairing modes and performing the antenna group allocation. The apparatus includes: a pairing unit, a calculation unit, an average value unit and a selecting unit. According to the present invention, cell average throughput and cell edge performance in Space Frequency Block Codes (SFBC) transmission scheme and Space Frequency Block Codes plus Frequency Switch Transmit Diversity (SFBC+FSTD) transmission scheme of the DAS, can be maximized.

Description

 Method and device for antenna group allocation of distributed antenna system

 The present invention relates to the field of wireless communication technologies, and in particular, to a method and apparatus for antenna group allocation of a distributed antenna system.

Background technique

 Distributed Antenna System (DAS) is an important development direction in the field of modern mobile communication technology. It is characterized in that the base station antennas are not concentrated in one place, but are distributed in different geographical locations in the cell. The distributed antenna system can be used. Against large-scale fading, especially for combating shadow fading due to occlusion of buildings or other objects.

 Space Frequency Block Codes (SFBC) is an open-loop transmit diversity scheme that applies Alamouti spatial time block coding to Orthogonal Frequency Division Multiplexing (OFDM) systems. The SFBC transmission scheme requires the use of two transmit antenna pairs to transmit the SFBC signal. When more than two transmit antennas are used at the transmitting end, the spatial frequency block coding may be combined with Frequency Switch Transmit Diversity (FSTD) to sequentially select a pair of antenna pairs for SFBC transmission in a certain order. Currently, spatial frequency block coding combined with frequency switched transmit diversity (SFBC + FSTD) transmission scheme is applied to the transmission of the Long Term Evolution (LTE) system broadcast channel and downlink control channel.

 Since the antennas serving the same cell in the DAS may be located in different geographical locations, when transmitting in the DAS using the SFBC transmission scheme or the SFBC+FSTD transmission scheme, they are divided into two antennas for pairing the transmitted SFBC signals. It will also be located in different geographical locations, which will cause the large-scale fading of the signals of the paired antennas received by the same User Equipment (UE) will be different, so how to perform SFBC transmission in DAS? Assigning antenna groups will have a significant impact on system performance.

In the prior art, the SFBC transmission scheme and the SFBC+FSTD transmitter are performed in the DAS. The antenna group allocation criterion is very small. The currently proposed antenna group allocation scheme adopts an antenna group allocation method of arbitrarily selecting available antenna pairs in the LTE system, that is, after arbitrarily selecting antenna pairing, each antenna is measured by the UE. The strength of the received signal is then fed back to the base station through the uplink control channel, and the base station performs power control according to the degree of signal attenuation of each distributed antenna to the UE.

 The inventors have found that such an antenna group allocation scheme has at least the following problems: This antenna group allocation scheme requires a closed loop feedback mechanism, and such a closed loop feedback mechanism cannot be realized in the transmission of a broadcast channel, because in the transmission of a broadcast channel, When the UE demodulates the broadcast channel, the system setting of the cell cannot be known, so the UE cannot implement feedback to the base station. Moreover, when such a scheme is applied to transmission of a downlink data channel, there may be problems such as UE feedback delay and inaccurate channel quality indication. Therefore, this scheme of arbitrarily selecting antenna group allocation with available antenna pairing is difficult to apply to the SFBC transmission scheme and the SFBC+FSTD transmission scheme in the DAS.

Summary of the invention

 Embodiments of the present invention provide a method and apparatus for antenna group allocation of a distributed antenna system capable of maximizing cell average throughput and cell edge performance of an SFBC transmission scheme and an SFBC+FSTD transmission scheme in DAS.

 Embodiments of the present invention use the following technical solutions:

 A method for antenna group allocation of a distributed antenna system includes:

 The 2n antennas serving the same cell are divided into n antenna groups, where n is a natural number greater than zero, wherein 2n antennas are divided into n antenna groups and there are M antenna pairing modes;

 Obtaining a distance d between each set of two antennas belonging to the same antenna pairing manner;

Obtaining an arithmetic mean value D _AV of n antenna groups d in each antenna pairing mode;

The allocation of the antenna group is performed by selecting the pairing mode in which the D _{AV is the} largest among the M antenna pairing modes. A device for distributing antenna groups of a distributed antenna system, comprising:

a pairing unit, configured to divide 2n antennas serving the same cell into n antenna groups, where n is a natural number greater than zero, wherein 2n antennas are divided into n antenna groups and M antenna pairing manners; The distance between each set of two antennas used to obtain the same antenna pairing d;

 Mean unit, used to obtain the arithmetic mean of n antenna groups d in each antenna pairing mode

D _AV ;

The selecting unit is configured to select a pairing mode in which the D _{AV is the} largest among the M antenna pairing modes, and perform antenna group allocation.

 The method and device for allocating an antenna group of a distributed antenna system according to an embodiment of the present invention divides 2n antennas in a distributed antenna system into n groups, and calculates an arithmetic mean value of distance between two antennas of n groups of matched SFBC signals. The maximum value is achieved, which maximizes the average cell throughput and cell edge performance of the SFBC transmission scheme and the SFBC+FSTD transmission scheme in the distributed antenna system structure.

DRAWINGS

 In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any inventive labor.

 1 is a flowchart of a method for allocating an antenna group of a distributed antenna system according to Embodiment 1 of the present invention; FIG. 2 is a schematic diagram of a site distribution of a distributed antenna system according to Embodiment 2 of the present invention;

 3 is a schematic structural diagram of a first antenna pairing manner according to Embodiment 2 of the present invention;

 4 is a schematic structural diagram of a second antenna pairing manner according to Embodiment 2 of the present invention;

 FIG. 5 is a schematic structural diagram of a third antenna pairing manner according to Embodiment 2 of the present invention; FIG.

 6 is a site distribution diagram of a distributed antenna system according to Embodiment 3 of the present invention;

 7 is a schematic structural diagram of a fourth antenna pairing manner according to Embodiment 3 of the present invention;

 8 is a schematic structural diagram of a fifth antenna pairing manner according to Embodiment 3 of the present invention;

 9 is a schematic structural diagram of a sixth antenna pairing manner according to Embodiment 3 of the present invention;

 FIG. 10 is a schematic structural diagram of an apparatus for allocating an antenna group of a distributed antenna system according to Embodiment 5 of the present invention.

detailed description The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

 Embodiment 1

 An embodiment of the present invention provides a method for allocating an antenna group of a distributed antenna system. As shown in FIG. 1, the method includes:

 101. The 2n antennas serving the same cell are divided into n antenna groups, where n is a natural number greater than zero, wherein 2n antennas are divided into n antenna groups and there are M antenna pairing modes;

The 2n antennas serving the same cell are divided into n groups, and two antennas in each group are paired to transmit SFBC signals, and n pairs of matched antennas in the cell jointly implement the SFBC+FSTD transmission scheme. According to the position of 2n antennas in the cell, M antenna pairing manners of dividing 2n antennas into n antenna groups are obtained, M=( 2n )! / ( n! *2 ⁿ ). The two antennas participating in the pairing may be from different base stations, or from between the base station and the relay node, or from between distributed antenna units, or from between the relay node and the distributed antenna unit.

 102. Obtain a distance d between each set of two antennas that belong to the same antenna pairing manner;

103. Obtain an arithmetic mean value D _AV of n antenna groups d in each antenna pairing manner;

 Calculate the arithmetic mean of the distance d between the two antennas of the n antenna groups for each antenna pairing method in the M antenna pairing mode.

104. Select a pairing mode in which the D _{AV is the} largest in the M antenna pairing mode.

The arithmetic mean value D _{AV of the} distance between the two antennas of the n antenna groups of each antenna pairing mode is compared, and the antenna pairing mode corresponding to the largest D _AV is selected to perform the distribution of the antenna group of the distributed antenna system.

In the embodiment of the present invention, the _DAS maximum pairing mode is selected to allocate the antenna group of the distributed antenna system, which can maximize the average cell throughput and the d-area edge of the SFBC transmission scheme and the SFBC+FSTD transmission scheme in the distributed antenna system structure. performance" Embodiment 2

 Embodiments of the present invention provide a method for antenna group allocation of a distributed antenna system, where the method includes:

 As shown in FIG. 2, in a hexagonal cell 1 in the embodiment of the present invention, there are three distributed antenna units 2, and three distributed antenna units 2 are respectively located at three vertices of a hexagonal cell 1, each distributed antenna. Two antennas are arranged on unit 2, that is, one hexagonal cell 1 is configured with a total of six antennas. The shortest distance 3 between the two distributed antenna elements 2 in the embodiment of the invention is d.

 The six-turn antenna of a hexagonal cell 1 is divided into three groups, and two sets of antennas are paired to transmit SFBC signals, and three sets of antennas jointly complete the SFBC+FSTD transmission scheme. According to the distribution position of the six antennas in the cell, that is, two antennas are distributed at three vertices of the hexagon, and there are three such matching methods, and the three matching modes are as shown in FIG. 3, FIG. 4 and FIG. Show.

 As shown in FIG. 3, the first antenna pairing mode 4 has a distributed antenna unit 2 on three vertices of the hexagonal cell 1, and two antennas on each distributed antenna unit 2, and two solid arrows in the figure. Represents two paired antennas, two dashed arrows represent two paired antennas, and two curved arrows represent two paired antennas.

In the three antenna pairing manners, the distance between the two antennas of the jth group of the three antenna groups of the first antenna pairing mode 4 is dj, and the two antennas of the jth group are on the same distributed antenna unit. When dj is 0; according to the formula, the arithmetic mean value D _AV 1 of the distance between the two antennas of the three antenna groups in the first antenna pairing method is 0.

 As shown in FIG. 4, the second antenna pairing mode 5 has a distributed antenna unit 2 on three vertices of the hexagonal cell 1, and two antennas on each distributed antenna unit 2, and two solid arrows in the figure. Represents two paired antennas, two dashed arrows represent two paired antennas, and two curved arrows represent two paired antennas.

In the three antenna pairing manners, the jth group of the three antenna groups of the second antenna pairing mode 5 The distance between the two antennas is d". When the two antennas of the jth group are on the same distributed antenna unit, dj is 0; according to the formula, two of the three antenna groups in the second antenna pairing mode 5 are calculated according to the formula. The arithmetic mean D _AV 2 of the distance between the antennas is 0.67d.

 As shown in FIG. 5, the third antenna pairing mode 6 has distributed antenna elements 2 on three vertices of the hexagonal cell 1, and two antennas on each distributed antenna unit 2, and two solid arrows in the figure. Represents two paired antennas, two dashed arrows represent two paired antennas, and two curved arrows represent two paired antennas.

计算出第二天线配对方式 5 中三个天线组的两个 天线间距离的算数平均值 D_AV3为 d。 In the three antenna pairing manners, the distance between the two antennas of the jth group of the three antenna groups of the third antenna pairing mode 6 is dj, and the two antennas of the jth group are on the same distributed antenna unit. When dj is 0; according to the formula

The arithmetic mean value D _AV 3 of the distance between the two antennas of the three antenna groups in the second antenna pairing mode 5 is calculated as d.

 Since d is greater than 0.67d greater than 0, the third antenna pairing mode 6 is selected to perform the allocation of the antenna group of the distributed antenna system.

A multi-cell (cell) system simulation is performed for the distributed antenna system structure in the embodiment of the present invention, and the LTE-compatible cell structure is used for the simulation, that is, 57 cells formed by the three layers of 19 base stations A (cell) system simulation model in which each base station serves three hexagonal cells. The DAS structure is constructed by adding a plurality of distributed antenna elements to the position of the distributed antenna unit according to the embodiment of the present invention on the basis of the above model. In the simulation, each cell has 12 user terminals (UEs), and each user terminal (UE) is configured with two receiving antennas, and adopts an IRC interference suppression receiving algorithm and a polling scheduling algorithm. The specific simulation parameters are shown in Table 1: Table 1 System simulation parameters

 Parameter name value

 Distance between LTE base stations 500m

 Bandwidth 10MHz

 Penetration loss 20dB

Path loss L = 15.3 + 37.6 log ₁₀ (R) iffi shadow fading standard deviation 8dB

 Small-scale fading Rayleigh flat fading (spatial channel uncorrelated) Transmitting power per cell 46dBm

 Thermal noise power "Pu density -174dBm/Hz

 User terminal noise figure 9dB

 The simulation compares the 5% interrupted spectral efficiency (SEout) and the average cell throughput (Tptav) of the three antenna pairing modes in the distributed antenna structure in the embodiment of the present invention. The simulation results are shown in Table 2: Table 2 Simulation results for various pairing schemes

 SEout Gain Tptav Gain

Scheme

 (bps/Hz/UE)

 (meter) (%) (Mbps/cell) (%) First antenna pairing method 0 0.062 - 27.0 - Second antenna pairing method 193 0.065 4.8 30.9 14.4

The third antenna pairing mode 288 0.067 8.0 32.7 21.1 It can be seen from the above simulation results that the third antenna pairing mode 6 can obtain the best interrupt spectrum efficiency and the average cell throughput for the distributed antenna structure in the embodiment of the present invention, so The method of antenna group allocation according to the embodiment of the present invention can maximize the cell average throughput and cell edge performance of the SFBC+FSTD transmission scheme in the distributed antenna system structure.

 Embodiment 3

Embodiments of the present invention provide a method for allocating an antenna group of a distributed antenna system, and the method Includes:

 As shown in FIG. 6, in a hexagonal cell 1 in the embodiment of the present invention, there are six distributed antenna units 2, and six distributed antenna units 2 are respectively located at six vertices of a hexagonal cell 1, each distributed. An antenna is disposed on the antenna unit 2, that is, a hexagonal cell 1 is configured with a total of six antennas. The shortest distance 3 between the two distributed antenna elements 2 in the embodiment of the invention is D.

 The six-turn antenna of a hexagonal cell 1 is divided into three groups, and each set of two antenna pairs transmits an SFBC signal, and the three sets of antennas jointly complete the SFBC+FSTD transmission scheme. According to the distribution position of the six antennas in the cell, that is, one antenna is distributed at the six vertices of the hexagon, and there are three such matching methods, and the three matching modes are as shown in FIG. 7, FIG. 8, and FIG. 9, respectively. .

 As shown in the fourth antenna pairing mode 7 shown in FIG. 7, the six vertices of the hexagonal cell 1 have distributed antenna elements 2, and each of the distributed antenna elements 2 has an antenna, and two solid arrows in the figure represent Two paired antennas, two dashed arrows represent two paired antennas, and two curved arrows represent two paired antennas.

计算出第四天线配对方式 7 中三个天线组的两个 天线间距离的算数平均值 D_AV4为 D。 The distance between the two antennas of the jth group of the three antenna groups of the fourth antenna pairing mode 7 is dj, and when the two antennas of the jth group are on the same distributed antenna unit, dj is 0;

The arithmetic mean value D _AV 4 of the distance between the two antennas of the three antenna groups in the fourth antenna pairing mode 7 is calculated as D.

 As shown in FIG. 8, the fifth antenna pairing mode 8 has a distributed antenna unit 2 at six vertices of the hexagonal cell 1, and an antenna on each distributed antenna unit 2, and two solid arrows in the figure represent Two paired antennas, two dashed arrows represent two paired antennas, and two curved arrows represent two paired antennas.

计算出鹩二夭钹配对方式 8 中三个天线组的两个 天线间距离的算数平均值 D_AV5为 1.49D。 The distance between the two antennas of the jth group of the three antenna groups of the fifth antenna pairing mode 8 is dj, and when the two antennas of the jth group are on the same distributed antenna unit, dj is 0;

Calculate two of the three antenna groups in pairing mode 8 The arithmetic mean D _AV 5 of the distance between the antennas is 1.49D.

 As shown in FIG. 9, the sixth antenna pairing mode 9 has a distributed antenna unit 2 on six vertices of the hexagonal cell 1, and an antenna on each distributed antenna unit 2, and two solid arrows in the figure represent Two paired antennas, two dashed arrows represent two paired antennas, and two curved arrows represent two paired antennas.

 The distance between the two antennas of the jth group of the three antenna groups of the sixth antenna pairing mode is dj, and when the two antennas of the jth group are on the same distributed antenna unit, dj is 0;

计算出第六天线配对方式 9 中三个天线组的两个 天线间距离的算数平均值 D_AV6为 2D。 According to the formula

The arithmetic mean value D _AV 6 of the distance between the two antennas of the three antenna groups in the sixth antenna pairing mode 9 is calculated to be 2D.

 Since 2D is greater than 1.49D and greater than D, the sixth antenna pairing mode 9 is selected for distribution of the antenna array of the distributed antenna system.

 A multi-cell (cell) system simulation is performed for the distributed antenna system structure in the embodiment of the present invention, and the LTE-compatible cell structure is used for the simulation, that is, 57 cells formed by the three layers of 19 base stations A (cell) system simulation model in which each base station serves three hexagonal cells. The DAS structure is constructed by adding a plurality of distributed antenna elements in accordance with the above model in accordance with the position of the distributed antenna unit in the embodiment of the present invention. In the simulation, each cell (cell) has 12 user terminals (UEs), and each user terminal (UE) is configured with two receiving antennas, and adopts an IRC interference suppression receiving algorithm and a polling scheduling algorithm. The specific simulation parameters are shown in Table 1:

 The simulation compares the 5% interrupt spectral efficiency (SEout) and the cell average throughput (Tptav) of the three antenna pairing modes in the distributed antenna structure in the embodiment of the present invention. The simulation results are shown in Table 2: Table 2 Embodiments of the present invention Simulation results for various pairing schemes

 SEout Gain Tptav Gain

Scheme

 (bps/Hz/UE) cell)

(meter) (%) (Mbps/ (%) Fourth antenna pairing method 167 0.113 - 34.3 - Fifth antenna pairing mode 248 0.118 4 4 35.1 2.3 The sixth antenna pairing mode is 0.123 8.8 35.9 4.7. As can be seen from the above simulation results, the sixth antenna pairing mode 9 can obtain the best interrupted spectrum efficiency and the average cell throughput for the distributed antenna structure in the embodiment of the present invention, so The antenna group allocation method of the embodiment of the present invention can maximize the structure of the distributed antenna system

Cell average throughput and cell edge performance of the SFBC+FSTD transmission scheme.

 Embodiment 4

 Embodiments of the present invention provide a method for antenna group allocation of a distributed antenna system, where the method includes:

 In the embodiment of the present invention, one cell has n antennas, and two transmit antennas are required to transmit SFBC signals in the cell. In the n antennas, the distance d between each two antennas is calculated, and the allocation of the antenna groups is selected. The two antennas with the largest distance d are paired for SFBC transmission.

 The method of antenna group allocation according to the embodiment of the present invention can maximize the cell average throughput and cell edge performance of the SFBC transmission scheme in the distributed antenna system structure.

 Embodiment 5

An embodiment of the present invention provides an apparatus for antenna group allocation of a distributed antenna system. As shown in FIG. 10, the apparatus includes: a pairing unit 111, a calculating unit 112, an average unit 113, and a selecting unit 114. The pairing unit 111 is configured to divide the 2n antennas serving the same cell into n antenna groups, where n is a natural number greater than zero, wherein the 2n antennas are divided into n antenna groups and there are M antenna pairing modes; Dividing 2n antennas into n antenna groups has M antenna pairing methods, where M=( 2n )! / ( n! *2 ⁿ ). The two antennas participating in the pairing are from different base stations, or from between the base station and the relay node, or from between distributed antenna units, or from between the relay node and the distributed antenna unit.

 The calculating unit 112 is configured to obtain a distance d between each set of two antennas belonging to the same antenna pairing manner;

The average unit 113 is configured to obtain an arithmetic mean value D _AV of n antenna groups d in each antenna pairing manner; Further, the averaging unit includes an averaging module, and the averaging module is configured to: in the M antenna pairing manner, a distance between the two antennas of the jth group of the n antenna groups of the i-th antenna pairing mode is (3⁄4) When the two antennas of the jth group are on the same distributed antenna unit, it is 0, where i is a natural number less than or equal to M, and j is a natural number less than or equal to n; the ith type is calculated according to the formula "^ ¹ " The arithmetic mean value D _{AV of the} distance between the two antennas of the n antenna groups in the antenna pairing mode.

The selecting unit 114 is configured to select a pairing mode in which the D _{AV is the} largest among the M antenna pairing modes, and perform antenna group allocation.

The D _{AVs of} all M antenna pairing modes are compared, and the antenna pairing method corresponding to the maximum D _AV is selected as the antenna group allocation method of the distributed antenna system.

 With the apparatus for antenna group allocation according to the embodiment of the present invention, the average cell throughput and cell edge performance of the SFBC+FSTD transmission scheme in the distributed antenna system structure can be maximized.

 Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus necessary general hardware, and of course, by hardware, but in many cases, the former is a better implementation. . Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, may be embodied in the form of a software product stored in a readable storage medium, such as a floppy disk of a computer. A hard disk or optical disk or the like includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform the methods described in various embodiments of the present invention.

 The above is only the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the claims.

Claims

Claim A method for allocating an antenna group of a distributed antenna system, comprising: dividing 2n antennas serving the same cell into n antenna groups, where n is a natural number greater than zero, wherein 2n antennas are used Divided into n antenna groups with M antenna pairing modes;  Obtaining a distance d between each set of two antennas belonging to the same antenna pairing manner; Obtaining an arithmetic mean value D _AV of n antenna groups d in each antenna pairing mode; The allocation of the antenna group is performed by selecting the pairing mode in which the D _{AV is the} largest among the M antenna pairing modes. 2. The method according to claim 1, wherein the dividing the 2n antennas into n antenna groups has M antenna pairing modes, wherein M=( 2n )! / ( n! *2 ⁿ ; ). 3. The method according to claim 1, wherein the obtaining the arithmetic mean value D _AV of the n antenna groups d in each antenna pairing manner comprises: In the M antenna pairing manner, the distance between the two antennas of the jth group of the n antenna groups of the i-th antenna pairing mode is when the two antennas of the jth group are on the same distributed antenna unit. , dij is 0, where 1 is a natural number less than or equal to M, and j is a natural number less than or equal to n; the arithmetic mean of the distance between the two antennas of the n antenna groups in the i-th antenna pairing method is calculated according to the formula "^" D _AV .  4. The method according to claim 1, wherein the paired antennas are from different base stations, or from between base stations and relay nodes, or from distributed antenna units, or from Between the relay node and the distributed antenna unit.  A device for allocating an antenna group of a distributed antenna system, comprising: a pairing unit, configured to divide 2n antennas serving the same cell into n antenna groups, where n is a natural number greater than zero, wherein , dividing 2n antennas into n antenna groups and having M antenna pairing modes; a calculation unit, configured to obtain a distance d between each set of two antennas belonging to the same antenna pairing manner; an average unit for obtaining an arithmetic mean value of n antenna groups d in each antenna pairing manner D _AV ; The selecting unit is configured to select a pairing mode in which the D _{AV is the} largest among the M antenna pairing modes, and perform antenna group allocation. The device according to claim 5, wherein the dividing 2n antennas into n antenna groups has M antenna pairing modes, wherein M=( 2n )! / ( n! *2 ⁿ ; ).  The device according to claim 5, wherein the average unit includes: an average value module, in the M antenna pairing manner, in the n antenna groups of the i-th antenna pairing mode The distance between the two antennas of the jth group is dij. When the two antennas of the jth group are on the same distributed antenna unit, dy is 0, where i is a natural number less than or equal to M, and j is less than or equal to n. Natural number;  =丄 ί The arithmetic mean value D _{AV of the} distance between the two antennas of the n antenna groups in the i-th antenna pairing mode is calculated according to the formula ^w X .  8. The apparatus according to claim 5, wherein the paired antennas are from different base stations, or from between base stations and relay nodes, or from distributed antenna units, or from Between the relay node and the distributed antenna unit.