CN114050852A - Beam forming method for inhibiting antenna coupling influence of large-scale MIMO system - Google Patents

Beam forming method for inhibiting antenna coupling influence of large-scale MIMO system Download PDF

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CN114050852A
CN114050852A CN202111371439.1A CN202111371439A CN114050852A CN 114050852 A CN114050852 A CN 114050852A CN 202111371439 A CN202111371439 A CN 202111371439A CN 114050852 A CN114050852 A CN 114050852A
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array antenna
antenna
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channel matrix
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CN114050852B (en
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庞立华
袁茵
柯增红
苏雨儿
魏倩
李�荣
代新冠
毛昕蓉
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Guangzhou Its Communication Equipment Co ltd
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Xian University of Science and Technology
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
    • H04B7/0617—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal for beam forming
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0602—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using antenna switching
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
    • H04B7/0802—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station using antenna selection
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Abstract

The invention discloses a beam forming method and a beam forming device for inhibiting antenna coupling influence of a large-scale MIMO system, which are applied to a compact planar array system and used for acquiring a first channel matrix of an array antenna when the electromagnetic mutual coupling effect of the array antenna is not considered; constructing a cross coupling matrix according to the array antenna parameters; calculating a second channel matrix based on the first channel matrix and the cross-coupling matrix; generating a first beam pattern according to the first channel matrix, and generating a second beam pattern according to the second channel matrix; solving to obtain a cross coupling suppression beam forming matrix of the array antenna by taking the minimized Euclidean distance between the first beam pattern and the second beam pattern as an optimization problem and the total power and the interference power of the array antenna as constraint conditions, and realizing the beam forming of the array antenna according to the cross coupling suppression beam forming matrix; the invention enables the performance of a digital beamforming system equipped with a large-scale non-compact antenna array to be close to that of a digital beamforming system equipped with a large-scale non-compact antenna array when equipped with a large-scale compact antenna array.

Description

Beam forming method for inhibiting antenna coupling influence of large-scale MIMO system
Technical Field
The invention belongs to the technical field of wireless communication, and particularly relates to a beam forming method for inhibiting antenna coupling influence in a large-scale MIMO system.
Background
A Massive multiple input multiple output (Massive MIMO) system can exploit spatial freedom deeply by configuring a Massive antenna array for a base station, so that the Massive MIMO system can serve multiple users by using the same time-frequency resource, and is considered as one of the most important physical layer key technologies of 6 th generation mobile communication (6G). For massive MIMO systems, due to the use of very large scale antenna arrays, one of the major challenges in base station deployment is that the number of antennas that can be installed is limited by the physical space that is actually available.
In a conventional MIMO system with a small number of antennas, a Uniform Linear Array (ULA) antenna structure is commonly used. However, since the size of the linear array is proportional to the number of antennas, large-scale deployment cannot be realized in the limited installation space at the top of the base station tower. In addition, the radiation declination angle of the linear array is fixed, and users can be distinguished only in the horizontal dimension, so that a certain angle blind area exists.
The planar antenna array realizes the arrangement of structures such as rectangle and circle by using an Active Antenna System (AAS), which not only can greatly increase the number of ports in a limited physical space and enlarge the scale of the antenna array, but also can realize the self-adaptive adjustment of radiation angles of horizontal and vertical dimensions. Therefore, the planar antenna array will become the main deployment form at the base station side of the massive MIMO system.
When the array deployment space is limited, the number of the array elements can be increased by reducing the array element spacing, and the configuration of more antennas can increase the transmission diversity of the system. However, the current or voltage signals on the antenna are affected by the adjacent antenna, which results in the limitation of the spacing between the antenna elements, that is, the voltage signals received by each antenna element generate induced currents on the antenna element itself, and these currents in turn excite a corresponding electromagnetic field, thereby affecting the adjacent antenna elements and limiting the performance of the array antenna.
Disclosure of Invention
The invention aims to provide a beam forming method for inhibiting antenna coupling influence of a large-scale MIMO system, which takes the minimum Euclidean distance of beam patterns before and after electromagnetic mutual coupling as an optimization problem to generate a beam forming matrix for inhibiting the electromagnetic coupling of adjacent antenna array elements in an array antenna.
The invention adopts the following technical scheme: a beam forming method for inhibiting antenna coupling influence of a large-scale MIMO system is applied to a compact planar array system and comprises the following steps:
acquiring a first channel matrix of the array antenna when the electromagnetic mutual coupling effect of the array antenna is not considered;
constructing a cross coupling matrix according to the array antenna parameters;
calculating a second channel matrix based on the first channel matrix and the cross-coupling matrix; the second channel matrix is a channel matrix when the electromagnetic mutual coupling effect of the array antennas is considered;
generating a first beam pattern according to the first channel matrix, and generating a second beam pattern according to the second channel matrix;
and solving to obtain a cross coupling suppression beam forming matrix of the array antenna by taking the minimized Euclidean distance between the first beam pattern and the second beam pattern as an optimization problem and the total power and the interference power of the array antenna as constraint conditions, and realizing the beam forming of the array antenna according to the cross coupling suppression beam forming matrix.
Further, the mutual coupling matrix is specifically:
C＝(ZL+ZA)(Z+ZLI)-1，
wherein C is a cross-coupling matrix, and dimension of C is NXN, ZLIs the load impedance of the array antenna, ZAThe antenna impedance of the array antenna is shown, Z is a mutual impedance matrix of the array antenna, the dimension of Z is NxN, I is a unit matrix, the dimension of I is NxN, and N is the total number of the antennas of the array antenna.
Further, the transimpedance matrix Z is composed of several Z(i,k)(j,l)Composition is carried out;
wherein Z is(i,k)(j,l)For the mutual impedance between the antenna of the ith row and the kth column and the antenna of the jth row and the lth column in the array antenna, i, j is equal to 1, …, Nv，k,l∈1,…,Nh，NvFor the number of rows of array elements in the array antenna, NhThe total number of the array antenna is N ═ Nv×Nh。
Further, Z(i,k)(j,l)Specifically, the formula is as follows:
Figure BDA0003362388670000031
wherein the content of the first and second substances,
Figure BDA0003362388670000032
μ0is the magnetic constant,. epsilon0Is an electrical constant, beta is a wave number,
Figure BDA0003362388670000033
λ0is the electromagnetic wavelength,/dipoleIs the array antenna dipole length, Ci(. is a cosine integral function, Si(. is a sinusoidal integral function, u0＝βd(i,k)(j,l)，d(i,k)(j,l)Is the distance between the antenna of the ith row and the kth column and the antenna of the jth row and the lth column in the array antenna,
Figure BDA0003362388670000034
d the distance between adjacent antenna elements in the array antenna,
Figure BDA0003362388670000035
further, calculating the second channel matrix comprises:
multiplying the cross coupling matrix C with the first channel matrix H to obtain a second channel matrix
Figure BDA0003362388670000036
Further, the optimization problem and constraint conditions are specifically:
the optimization problem is
Figure BDA0003362388670000037
The constraint conditions for the total power are:
Figure BDA0003362388670000038
the constraint condition of interference power is
Figure BDA0003362388670000039
Wherein the content of the first and second substances,
Figure BDA00033623886700000310
in order to be the second beam pattern,
Figure BDA00033623886700000311
representing a mutually coupled channel matrix, S, between the array antenna and a user k taking into account the electromagnetic mutual coupling effect of the array antennaideal＝hkukIs the first beam pattern, hkRepresenting the channel matrix, w, between the array antenna and the user k without taking into account the effect of electromagnetic mutual coupling of the array antennakFor a cross-coupling-suppressing beamforming matrix for user k, ukAn initial digital beamforming matrix for user k, without considering the electromagnetic mutual coupling effect of the array antennas, P is the total transmit power of the array antennas,
Figure BDA0003362388670000041
to account for the autocorrelation matrix of the user j channel response when considering the electromagnetic mutual coupling effect of the array antenna, epsilon is the interference power threshold.
Further, the solving to obtain the cross-coupling suppression beamforming matrix of the array antenna includes:
according to optimization problems
Figure BDA0003362388670000042
Constructing a Lagrangian function and a KKT condition according to constraint conditions;
solving a Lagrange function by adopting a Lagrange multiplier method to obtain cross coupling suppression beam forming matrixes of K users;
and combining the cross coupling restraining beam forming matrixes of the K users to obtain the cross coupling restraining beam forming matrix of the array antenna.
Further, the lagrangian function is specifically:
Figure BDA0003362388670000043
wherein the content of the first and second substances,
Figure BDA0003362388670000044
for the mutual coupling channel matrix h between the array antenna and the user k in consideration of the electromagnetic mutual coupling effect of the array antennakIn order to obtain a mutual coupling channel matrix from the array antenna to a user k without considering the electromagnetic mutual coupling effect of the array antenna, lambda and mu are both Lambertian multipliers;
the KKT condition is specifically as follows:
Figure BDA0003362388670000051
wherein the content of the first and second substances,
Figure BDA0003362388670000052
an autocorrelation matrix of the user k channel response is taken into account when considering the effect of electromagnetic mutual coupling of the array antennas.
Another technical solution of the present invention is a beam forming apparatus for a large-scale MIMO system to suppress antenna coupling effects, applied to a compact planar array system, comprising:
the device comprises an acquisition module, a receiving module and a processing module, wherein the acquisition module is used for acquiring a first channel matrix of an array antenna when the electromagnetic mutual coupling effect of the array antenna is not considered;
the construction module is used for constructing a mutual coupling matrix according to the array antenna parameters;
a calculation module for calculating a second channel matrix based on the first channel matrix and the cross-coupling matrix; the second channel matrix is a channel matrix when the electromagnetic mutual coupling effect of the array antennas is considered;
the generating module is used for generating a first beam directional diagram according to the first channel matrix and generating a second beam directional diagram according to the second channel matrix;
and the solving module is used for solving to obtain a cross coupling suppression beam forming matrix of the array antenna by taking the Euclidean distance of the minimized first beam directional diagram and the minimized second beam directional diagram as an optimization problem and the total power and the interference power of the array antenna as constraint conditions, and realizing the beam forming of the array antenna according to the cross coupling suppression beam forming matrix.
Another technical solution of the present invention is a beamforming method and apparatus for a massive MIMO system to suppress antenna coupling effects, including a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor implements the beamforming method for a massive MIMO system to suppress antenna coupling effects when executing the computer program.
The invention has the beneficial effects that: according to the invention, by considering the electromagnetic coupling effect among array elements in the array antenna, a mutual coupling matrix is introduced, and the minimization of Euclidean distance of beam patterns before and after the introduction of the mutual coupling matrix is used as a target, the mutual coupling inhibiting beam forming matrix is calculated, the beam pattern distortion caused by the electromagnetic mutual coupling effect is inhibited, the point-to-point transmission capability is improved, and the performance of the digital beam forming system provided with a large-scale non-compact antenna array is close to that of the digital beam forming system provided with the large-scale non-compact antenna array when the large-scale compact antenna array is provided.
Drawings
Fig. 1 is a flowchart of a beamforming method for suppressing antenna coupling effect in a massive MIMO system according to the present invention;
fig. 2 is a schematic diagram of a module structure of a beam forming apparatus for suppressing antenna coupling influence in a large-scale MIMO system according to the present invention;
FIG. 3 is a comparison graph of the verification effect in the embodiment of the present invention.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
In the existing array antenna, when the array element spacing is smaller than a certain value, the array beam pattern is distorted due to the electromagnetic mutual coupling effect between the array elements. In order to suppress the beam pattern distortion caused by the electromagnetic mutual coupling effect, the large-scale MIMO system must optimize and adjust the antenna radiation direction at the base station end by changing the weighting coefficient of the antenna array elements, i.e., utilize effective beam forming processing to gather the received signal energy and improve the point-to-point transmission capability.
The invention discloses a beam forming method for inhibiting antenna coupling influence of a large-scale MIMO system, which is applied to a compact planar array system and comprises the following steps of: s110, when the electromagnetic mutual coupling effect of the array antenna is not considered, a first channel matrix of the array antenna is obtained; s120, constructing a cross coupling matrix according to the array antenna parameters; s130, calculating a second channel matrix based on the first channel matrix and the cross coupling matrix; the second channel matrix is a channel matrix when the electromagnetic mutual coupling effect of the array antennas is considered; s140, generating a first beam pattern according to the first channel matrix, and generating a second beam pattern according to the second channel matrix; s150, solving to obtain a cross coupling suppression beam forming matrix of the array antenna by taking the minimized Euclidean distance between the first beam pattern and the second beam pattern as an optimization problem and the total power and the interference power of the array antenna as constraint conditions, and realizing beam forming of the array antenna according to the cross coupling suppression beam forming matrix.
According to the invention, by considering the electromagnetic coupling effect among array elements in the array antenna, a mutual coupling matrix is introduced, and the minimization of Euclidean distance of beam patterns before and after the introduction of the mutual coupling matrix is used as a target, the mutual coupling inhibiting beam forming matrix is calculated, the beam pattern distortion caused by the electromagnetic mutual coupling effect is inhibited, the point-to-point transmission capability is improved, and the performance of the digital beam forming system provided with a large-scale non-compact antenna array is close to that of the digital beam forming system provided with the large-scale non-compact antenna array when the large-scale compact antenna array is provided.
According to the invention, the beam distortion before and after the electromagnetic mutual coupling effect is minimized, namely the minimum Euclidean distance of K user beam pattern before and after the electromagnetic mutual coupling effect is considered, the beam forming matrix is designed, the point-to-point transmission capability is improved, and the maximum spectrum efficiency is obtained.
In the embodiment of the invention, a Saleh-Vallenzuela narrowband cluster channel model is adopted, and a channel vector is the sum of contributions of scattering clusters. Obtaining a channel matrix before considering electromagnetic mutual coupling effect, H ═ H1,h2,...,hK]H，hkAnd expressing a channel matrix from the array antenna to a user K, wherein the K is the total number of users in the cell. Zero Forcing (ZF) beamforming is used for initial digital beamforming for eliminating interference between users, and a channel matrix H-H before electromagnetic mutual coupling effect is considered in calculation1,h2,...,hK]HTo obtain the initial digital beam forming matrix U ═ H of the user without considering the electromagnetic mutual coupling effectH(HHH)-1＝[u1,u2,...,uK]。
In one embodiment, the mutual coupling matrix is modeled between linear dipole antennas of length l, which are placed on a planar array with a uniform square grid and rectangular boundaries. Assuming a vertical deployment NvRoot antenna, disposed N in horizontal directionhRoot antenna, base station total antenna number N ═ Nv×NhMutual coupling matrix for electromagnetic mutual coupling between array elements
Figure BDA0003362388670000081
To describe, the mutual coupling matrix is specifically:
C＝(ZL+ZA)(Z+ZLI)-1，
wherein C is a cross-coupling matrix, and the dimension of C is NxN, ZLBeing the load of an array antennaImpedance, ZAThe antenna impedance of the array antenna is represented by Z, the dimension of Z is N multiplied by N, I is a unit matrix, and the dimension of I is N multiplied by N.
In some embodiments, the transimpedance matrix Z consists of a number of Z(i,k)(j,l)Composition Z(i,k)(j,l)For the mutual impedance between the antenna of the ith row and the kth column and the antenna of the jth row and the lth column in the array antenna, i, j is equal to 1, …, Nv，k,l∈1,…,Nh，NvFor the number of rows of array elements in the array antenna, NhIs the number of columns of array elements in the array antenna.
In this embodiment, the transimpedance Z is obtained by the EMF (induced electromotive force) method using a flush-type arrangement(i,k)(j,l)The calculation formula is as follows:
Figure BDA0003362388670000082
wherein the content of the first and second substances,
Figure BDA0003362388670000083
μ0is the magnetic constant,. epsilon0Beta is a wave number (i.e., the number of wave cycles per unit length in the direction in which the electromagnetic wave propagates is a wave number),
Figure BDA0003362388670000084
λ0is the electromagnetic wavelength,/dipoleIs the array antenna dipole length, Ci(. is a cosine integral function, Si(. is a sinusoidal integral function, u0＝βd(i,k)(j,l)，d(i,k)(j,l)Is the distance between the antenna of the ith row and the kth column and the antenna of the jth row and the lth column in the array antenna,
Figure BDA0003362388670000091
d the distance between adjacent antenna elements in the array antenna,
Figure BDA0003362388670000092
as a specific way of carrying out the present invention,calculating the second channel matrix comprises: and multiplying the cross coupling matrix and the first channel matrix to obtain a second channel matrix. I.e. multiplication of the cross coupling matrix and the channel matrix H is equivalent to a cross coupling channel matrix
Figure BDA0003362388670000093
Figure BDA0003362388670000094
The representation considers the mutual coupling channel matrix between the base station and the user k after the electromagnetic mutual coupling.
There are many ways to design the beamforming matrix of the array antenna, and in this embodiment, it is implemented by controlling the minimum euclidean distance of the beam pattern (because the electromagnetic mutual coupling may cause distortion of the beam pattern, so that the beam pattern after the coupling effect is close to the beam pattern without the coupling effect, i.e. the difference between the two is minimized, in order to suppress the coupling effect). Specifically, in order to minimize the distortion of the beam pattern and obtain the maximum spectral efficiency, the design of the cross-coupling suppression beam forming matrix aims to minimize the euclidean distance of the user beam pattern before and after considering the electromagnetic cross-coupling effect, and the interference between users is eliminated by forming the null in the beam pattern of the desired user in the direction of other users, so as to obtain the maximum spectral efficiency. The minimization of beam distortion can be equivalent to the minimization of euclidean distance of the beam patterns before and after the electromagnetic mutual coupling effect is considered, and this process can be expressed as:
Figure BDA0003362388670000095
i.e. the optimization problem is
Figure BDA0003362388670000096
In order to ensure that the transmitting power of K users is less than or equal to the transmitting power of the base station end, the constraint condition of the total power is as follows:
Figure BDA0003362388670000097
the constraint condition of interference power is
Figure BDA0003362388670000101
Wherein the content of the first and second substances,
Figure BDA0003362388670000102
for the second beam pattern, Sideal＝hkukIs a first beam pattern, wkIs the beamforming matrix of the kth user, P is the total transmit power of the array antenna,
Figure BDA0003362388670000103
and epsilon is an interference power threshold value for an autocorrelation matrix of the j-th user channel response when the electromagnetic mutual coupling effect of the array antenna is considered.
The embodiment of the invention also provides a specific method for solving and obtaining the cross coupling suppression beam forming matrix of the array antenna. The method comprises the following steps:
constructing a Lagrangian function and a KKT condition according to the optimization problem and the constraint condition; solving a Lagrange function by adopting a Lagrange multiplier method to obtain cross coupling suppression beam forming matrixes of K users; and combining the cross coupling restraining beam forming matrixes of the K users to obtain the cross coupling restraining beam forming matrix of the array antenna.
The optimization problem can be expressed as:
Figure BDA0003362388670000104
regarding the constraint condition, it is expected that the beam of user k forms a null in the direction of user j, which can be equivalent to that the interference generated by the kth user to the jth user is 0, and this process can be expressed as:
Figure BDA0003362388670000105
in order to eliminate the interference of the user k to other users j (j ≠ k), the null direction of the beam pattern of the user k is aligned to the expected direction of other users j (j ≠ k). The constraint that the interference power is 0 is too strong for the optimization problem, so the power can be scaled to 0 to a small real number epsilon, i.e. the interference power constraint can be expressed as:
Figure BDA0003362388670000106
the optimization problem can thus be expressed as:
Figure BDA0003362388670000111
order to
Figure BDA0003362388670000112
Minimization of target Ga (w) for optimization problem P1k) To wkCalculating the second order partial derivative
Figure BDA0003362388670000113
Therefore, the above optimization problem is a convex problem, and the lagrangian function is constructed as follows:
Figure BDA0003362388670000114
wherein the content of the first and second substances,
Figure BDA0003362388670000115
for the mutual coupling channel matrix h between the array antenna and the user k in consideration of the electromagnetic mutual coupling effect of the array antennakFor mutual coupling channel matrix, u, between array antenna and user k without taking into account electromagnetic mutual coupling effect of array antennakIn order to obtain an initial digital precoding matrix of a user k without considering the electromagnetic mutual coupling effect of the array antenna, lambda and mu are both Lambertian multipliers;
the KKT condition is specifically as follows:
Figure BDA0003362388670000121
wherein the content of the first and second substances,
Figure BDA0003362388670000122
an autocorrelation matrix of the k-th user channel response to account for the electromagnetic mutual coupling effects of the array antennas.
Finally, the decoupling wave beam forming w can be obtained according to the Lagrange multiplier methodk：
Figure BDA0003362388670000123
In summary, the design goal of the mutual coupling inhibiting wave beam shaper is to reduce the wave beam pattern distortion caused by the electromagnetic coupling effect of the compact array, and completely eliminate the interference between users by mapping the expected user signals to the null space of other users, so as to obtain the maximum spectrum efficiency; the performance of the traditional digital beamforming is reduced when a system deploys a compact antenna array, but the performance of the method provided by the invention when the system deploys the compact antenna array is almost not lost compared with the traditional digital beamforming scheme when a non-compact antenna array is deployed; more antenna elements can be deployed in the limited physical space of the base station, and higher frequency spectrum efficiency can be obtained with lower implementation complexity.
In the present invention, the method of the present invention was also simulated to verify its validity. The effectiveness of the digital beamforming scheme is verified specifically by MATLAB simulation. Adopting a geometric Saleh-Vallenzuela narrowband cluster channel model, setting the number of channel clusters to be 8, the number of sub-paths in each cluster to be 10, and obeying the arrival angle and the departure angle to 0,2 pi]Are uniformly distributed. The base station is provided with 256 transmitting antennas and 256 RF links, 16 antennas are deployed in the vertical direction, 16 antennas are deployed in the horizontal direction, and the spacing between antenna array elements is 0.1 lambda0A compact planar array of (a); the mobile terminal has 2 users, each user terminal is provided with 4 receiving antennas and 4 RF links, 2 antennas are deployed in the vertical direction and 2 antennas are deployed in the horizontal direction, and the spacing between antenna elements is 0.5 lambda0A non-compact planar array of (a).
Figure 3 shows the spectral efficiency achieved with different beamforming schemes as a function of the signal-to-noise ratio. As can be seen from the figure, on the premise of a compact planar array system with densely arranged antenna array units, the performance of the cross coupling suppression beamforming algorithm of the present invention is close to that of the conventional digital beamforming scheme of a non-compact planar array system, and is much greater than that of the conventional digital beamforming scheme of the compact planar array system. If the complexity factor is considered comprehensively, the cross coupling suppression beamforming algorithm not only has low complexity, but also suppresses the influence of the electromagnetic cross coupling effect and obtains high spectrum efficiency. In fig. 3, when the signal-to-noise ratio is 10dB, the spectral efficiency of the cross-coupling rejection beamforming algorithm of the present invention is 59.0975bit/s/Hz, which is close to 60.2138bit/s/Hz of the conventional digital beamforming scheme of the non-compact planar array system, and is much higher than 15.4598bit/s/Hz of the conventional digital beamforming scheme of the compact planar array system.
Therefore, the invention optimizes and adjusts the antenna radiation direction by changing the weighting coefficient of the antenna array element, namely utilizes effective beam forming processing to gather the received signal energy, inhibits the beam pattern distortion caused by electromagnetic mutual coupling effect, improves the point-to-point transmission capability, and leads the performance of the digital beam forming system equipped with a large-scale non-compact antenna array to be close to that of the digital beam forming system equipped with a large-scale non-compact antenna array when being equipped with a large-scale compact antenna array.
The invention also discloses a beam forming device for inhibiting antenna coupling influence of a large-scale MIMO system, which is applied to a compact planar array system and comprises the following components:
an obtaining module 210, configured to obtain a first channel matrix of the array antenna without considering an electromagnetic mutual coupling effect of the array antenna; a constructing module 220, configured to construct a mutual coupling matrix according to the array antenna parameters; a calculating module 230, configured to calculate a second channel matrix based on the first channel matrix and the mutual coupling matrix; the second channel matrix is a channel matrix when the electromagnetic mutual coupling effect of the array antennas is considered; a generating module 240, configured to generate a first beam pattern according to the first channel matrix, and generate a second beam pattern according to the second channel matrix; and the solving module 250 is configured to solve the cross coupling suppression beamforming matrix of the array antenna by using the minimized euclidean distance between the first beam pattern and the second beam pattern as an optimization problem and using the total power and the interference power of the array antenna as constraint conditions, and implement beamforming of the array antenna according to the cross coupling suppression beamforming matrix.
It should be noted that, for the information interaction, execution process, and other contents between the modules of the apparatus, the specific functions and technical effects of the embodiments of the method are based on the same concept, and thus reference may be made to the section of the embodiments of the method specifically, and details are not described here.
It will be clear to those skilled in the art that, for convenience and simplicity of description, the foregoing division of the functional modules is merely illustrated, and in practical applications, the above function distribution may be performed by different functional modules according to needs, that is, the internal structure of the apparatus is divided into different functional modules to perform all or part of the above described functions. Each functional module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional modules are only used for distinguishing one functional module from another, and are not used for limiting the protection scope of the application. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
The invention discloses a beam forming method device for inhibiting antenna coupling influence of a large-scale MIMO system, which comprises a memory, a processor and a computer program which is stored in the memory and can be operated on the processor, wherein the beam forming method for inhibiting the antenna coupling influence of the large-scale MIMO system is realized when the processor executes the computer program.
The device can be a desktop computer, a notebook, a palm computer, a cloud server and other computing equipment. The apparatus may include, but is not limited to, a processor, a memory. Those skilled in the art will appreciate that the apparatus may include more or fewer components, or some components in combination, or different components, and may also include, for example, input-output devices, network access devices, etc.
The Processor may be a Central Processing Unit (CPU), or other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The memory may in some embodiments be an internal storage unit of the device, such as a hard disk or a memory of the device. The memory may also be an external storage device of the apparatus in other embodiments, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), etc. provided on the apparatus. Further, the memory may also include both an internal storage unit and an external storage device of the apparatus. The memory is used for storing an operating system, application programs, a BootLoader (BootLoader), data, and other programs, such as program codes of the computer programs. The memory may also be used to temporarily store data that has been output or is to be output.
In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment. Those of ordinary skill in the art will appreciate that the various illustrative modules and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

Claims (10)

1. A beam forming method for inhibiting antenna coupling influence of a large-scale MIMO system is characterized by being applied to a compact planar array system and comprising the following steps:
acquiring a first channel matrix of the array antenna when the electromagnetic mutual coupling effect of the array antenna is not considered;
constructing a mutual coupling matrix according to the array antenna parameters;
calculating a second channel matrix based on the first channel matrix and the mutual coupling matrix; wherein the second channel matrix is a channel matrix considering electromagnetic mutual coupling effect of the array antennas;
generating a first beam pattern according to the first channel matrix, and generating a second beam pattern according to the second channel matrix;
and solving to obtain a cross coupling suppression beam forming matrix of the array antenna by taking the minimized Euclidean distance between the first beam pattern and the second beam pattern as an optimization problem and the total power and the interference power of the array antenna as constraint conditions, and realizing the beam forming of the array antenna according to the cross coupling suppression beam forming matrix.
2. The method of claim 1, wherein the mutual coupling matrix is specifically:
C＝(ZL+ZA)(Z+ZLI)-1，
wherein C is a cross-coupling matrix, and the dimension of C is NxN, ZLIs the load impedance of the array antenna, ZAThe antenna impedance of the array antenna is shown, Z is a mutual impedance matrix of the array antenna, the dimension of Z is NxN, I is a unit matrix, the dimension of I is NxN, and N is the total number of the antennas of the array antenna.
3. The method as claimed in claim 2, wherein the transimpedance matrix Z is formed by a plurality of Z' s(i,k)(j,l)Composition is carried out;
wherein Z is(i,k)(j,l)For the ith row and the kth column in the array antennaAnd the antenna in the jth row and the ith column, i, j ∈ 1, …, Nv，k,l∈1,…,Nh，NvFor the number of rows of array elements in the array antenna, NhThe total number of the array antenna is N ═ Nv×Nh。。
4. The method of claim 3, wherein Z is the number of antennas coupled in the MIMO system(i,k)(j,l)Specifically, the formula is as follows:
Figure FDA0003362388660000021
wherein the content of the first and second substances,
Figure FDA0003362388660000022
μ0is the magnetic constant,. epsilon0Is an electrical constant, beta is a wave number,
Figure FDA0003362388660000023
λ0is the electromagnetic wavelength,/dipoleIs the array antenna dipole length, Ci(. is a cosine integral function, Si(. is a sinusoidal integral function, u0＝βd(i,k)(j,l)，d(i,k)(j,l)Is the distance between the antenna of the ith row and the kth column and the antenna of the jth row and the lth column in the array antenna,
Figure FDA0003362388660000024
d the distance between adjacent antenna elements in the array antenna,
Figure FDA0003362388660000025
5. the method as claimed in any of claims 1-4, wherein the calculating the second channel matrix comprises:
multiplying the cross coupling matrix C with the first channel matrix H to obtain the second channel matrix
Figure FDA0003362388660000026
6. The method of claim 5, wherein the optimization problem and the constraint condition specifically include:
the optimization problem is
Figure FDA0003362388660000027
The constraint condition of the total power is as follows:
Figure FDA0003362388660000028
the constraint condition of the interference power is
Figure FDA0003362388660000029
Wherein the content of the first and second substances,
Figure FDA00033623886600000210
for the purpose of the second beam pattern,
Figure FDA00033623886600000211
representing a mutually coupled channel matrix, S, between the array antenna and a user k taking into account the electromagnetic mutual coupling effect of the array antennaideal＝hkukFor said first beam pattern, hkRepresenting the channel matrix, w, between the array antenna and the user k without taking into account the effect of electromagnetic mutual coupling of the array antennakFor a cross-coupling-suppressing beamforming matrix for user k, ukAn initial digital beamforming matrix for user k, without considering the electromagnetic mutual coupling effect of the array antennas, P is the total transmit power of the array antennas,
Figure FDA0003362388660000031
to account for the autocorrelation matrix of the user j channel response when considering the electromagnetic mutual coupling effect of the array antenna, epsilon is the interference power threshold.
7. The method as claimed in claim 6, wherein the solving for the cross coupling suppression beamforming matrix of the array antenna comprises:
according to optimization problems
Figure FDA0003362388660000032
Constructing a Lagrangian function and a KKT condition according to the constraint conditions;
solving the Lagrange function by adopting a Lagrange multiplier method to obtain cross coupling suppression beam forming matrixes of K users;
and combining the cross coupling restraining beam forming matrixes of the K users to obtain the cross coupling restraining beam forming matrix of the array antenna.
8. The method of claim 1, wherein the lagrangian function is specifically as follows:
Figure FDA0003362388660000033
wherein the content of the first and second substances,
Figure FDA0003362388660000034
for the mutual coupling channel matrix h between the array antenna and the user k in consideration of the electromagnetic mutual coupling effect of the array antennakIn order to obtain a channel matrix from the array antenna to a user k without considering the electromagnetic mutual coupling effect of the array antenna, lambda and mu are both Lambertian multipliers;
the KKT condition is specifically as follows:
Figure FDA0003362388660000041
wherein the content of the first and second substances,
Figure FDA0003362388660000042
an autocorrelation matrix of the k-th user channel response to account for the electromagnetic mutual coupling effects of the array antennas.
9. A beam forming device for inhibiting antenna coupling influence of a large-scale MIMO system is characterized by being applied to a compact planar array system and comprising:
the device comprises an acquisition module, a receiving module and a processing module, wherein the acquisition module is used for acquiring a first channel matrix of an array antenna when the electromagnetic mutual coupling effect of the array antenna is not considered;
the construction module is used for constructing a mutual coupling matrix according to the array antenna parameters;
a calculation module for calculating a second channel matrix based on the first channel matrix and the mutual coupling matrix; wherein the second channel matrix is a channel matrix considering electromagnetic mutual coupling effect of the array antennas;
a generating module, configured to generate a first beam pattern according to the first channel matrix, and generate a second beam pattern according to the second channel matrix;
and the solving module is used for solving to obtain a cross coupling suppression beam forming matrix of the array antenna by taking the minimized Euclidean distance between the first beam pattern and the second beam pattern as an optimization problem and the total power and the interference power of the array antenna as constraint conditions, and realizing the beam forming of the array antenna according to the cross coupling suppression beam forming matrix.
10. A beamforming method apparatus for a massive MIMO system to suppress antenna coupling effect, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the beamforming method for a massive MIMO system to suppress antenna coupling effect as claimed in any one of claims 1 to 8.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114884598A (en) * 2022-04-20 2022-08-09 华中科技大学 Super-directional antenna array beam forming vector determination method based on coupling matrix

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090309802A1 (en) * 2006-06-30 2009-12-17 Ulf Lindgren Re-configurable antenna and a method for acquiring a configuration of a re-configurable antenna
US20170019154A1 (en) * 2015-07-16 2017-01-19 Spirent Communications, Inc. Massive mimo array emulation
CN107038299A (en) * 2017-04-10 2017-08-11 西安电子科技大学 A kind of anamorphic array Antenna Far Field directional diagram compensation method for considering mutual coupling effect
CN108923833A (en) * 2018-06-22 2018-11-30 南京航空航天大学 A kind of transmitting terminal wave beam method for precoding inhibited towards mutual coupling of antenna effect
CN113315560A (en) * 2021-05-28 2021-08-27 西安电子科技大学 Beam forming method of compact planar array Massive MIMO system
CN113315552A (en) * 2021-05-26 2021-08-27 西安电子科技大学 Energy efficiency optimization method of compact planar antenna array Massive MIMO system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090309802A1 (en) * 2006-06-30 2009-12-17 Ulf Lindgren Re-configurable antenna and a method for acquiring a configuration of a re-configurable antenna
US20170019154A1 (en) * 2015-07-16 2017-01-19 Spirent Communications, Inc. Massive mimo array emulation
CN107038299A (en) * 2017-04-10 2017-08-11 西安电子科技大学 A kind of anamorphic array Antenna Far Field directional diagram compensation method for considering mutual coupling effect
CN108923833A (en) * 2018-06-22 2018-11-30 南京航空航天大学 A kind of transmitting terminal wave beam method for precoding inhibited towards mutual coupling of antenna effect
CN113315552A (en) * 2021-05-26 2021-08-27 西安电子科技大学 Energy efficiency optimization method of compact planar antenna array Massive MIMO system
CN113315560A (en) * 2021-05-28 2021-08-27 西安电子科技大学 Beam forming method of compact planar array Massive MIMO system

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
孙长果等: "考虑互耦影响下的智能天线数字波束赋形", 《微波学报》, no. 01, 30 April 2003 (2003-04-30) *
谢佳轩等: "互耦效应对波束赋形天线的影响分析", 《信息技术》, no. 01, 25 January 2016 (2016-01-25) *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114884598A (en) * 2022-04-20 2022-08-09 华中科技大学 Super-directional antenna array beam forming vector determination method based on coupling matrix
CN114884598B (en) * 2022-04-20 2023-03-14 华中科技大学 Super-directional antenna array beam forming vector determination method based on coupling matrix

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