Self-interference suppression method for multi-beam simultaneous transceiving array

Abstract

The invention relates to a multi-beam simultaneous transceiving array self-interference suppression method. The method comprises the following steps: S1, constructing a self-interference suppression scene; s2, optimizing transmitting and receiving beam forming coefficients in an airspace by using an alternating iterative algorithm; s3, calculating a reconstruction coefficient of the linear filter in a digital domain according to a least square criterion; and S4, realizing self-interference suppression in the multi-beam simultaneous transceiving array by using the transmitting and receiving beam forming coefficients and the reconstruction coefficient. According to the method, an alternate iteration algorithm of a space domain is utilized to simultaneously optimize transmitting and receiving beam forming coefficients and a least square criterion of a digital domain to calculate a reconstruction coefficient, so that high-power self-interference in a multi-beam simultaneous transmitting and receiving array is effectively inhibited, and the isolation of the transmitting and receiving array is improved; the method has important guiding significance for realizing wireless communication with large communication capacity, wide coverage range and low transmission delay in actual engineering.

Description

Technical Field

[0001] The present invention relates to simultaneous transceiver technology, and particularly to a method for suppressing self-interference of a multi-beam simultaneous transceiver array. Background Art

[0002] The multi-beam simultaneous transceiver array supports transmitting and receiving multiple signals at the same time and frequency, significantly improving communication efficiency and spectrum utilization rate, realizing wireless communication with large communication capacity, wide coverage range, and low transmission delay, and promoting the development of the Internet of Everything communication network. However, due to the close distance between the transceiver arrays, multiple high-power signals of the transmitting array will cause serious self-interference to the receiving array, reducing the reception quality of the desired signal, and even causing the receiving channel to saturate and resulting in communication interruption. Therefore, self-interference suppression is a key technology for realizing a multi-beam simultaneous transceiver array.

[0003] Regarding the self-interference suppression method for a single-beam simultaneous transceiver array, the academic community has conducted relatively sufficient research. The self-interference effect is mainly reduced through spatial domain, radio frequency domain, and digital domain self-interference suppression technologies. In order to fully suppress self-interference, multiple self-interference suppression technologies are usually combined to suppress self-interference step by step. However, the existing research does not involve the self-interference suppression method for a multi-beam simultaneous transceiver array. Directly using the self-interference suppression method for a single-beam simultaneous transceiver array in a multi-beam simultaneous transceiver array will result in poor self-interference suppression performance. Therefore, the self-interference suppression method for a multi-beam simultaneous transceiver array is one of the key technologies that urgently need to be studied at present. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for suppressing self-interference of a multi-beam simultaneous transceiver array. By combining the alternating iteration algorithm in the spatial domain and the least squares criterion in the digital domain, the self-interference in the multi-beam simultaneous transceiver array is greatly suppressed, the isolation degree of the transceiver array is improved, and wireless communication with large communication capacity, wide coverage range, and low transmission delay is realized.

[0005] The purpose of the present invention is achieved through the following technical solutions: A method for suppressing self-interference of a multi-beam simultaneous transceiver array, the method comprising the following steps:

[0006] S1. Mathematically characterize the transmitted signal, coupled channel, received signal, and reconstructed signal of the multi-beam simultaneous transceiver array;

[0007] S2. Optimize the transmit and receive beamforming coefficients in the spatial domain using the alternating iteration algorithm;

[0008] S3. Calculate the reconstruction coefficients of the linear filter according to the least squares criterion in the digital domain.

[0009] S4. Use the transmit and receive beamforming coefficients and the reconstruction coefficients to achieve self-interference suppression in the multi-beam simultaneous transceiver array.

[0010] The specific steps of step S1 include:

[0011] The transmitting array in the multi-beam simultaneous transceiver array includes J transmitting elements, and the receiving array includes K receiving elements. Denote that there are M transmitting signals x1(n), x2(n), …, x M (n) at the transmitter, and the power of the m-th transmitting signal is:

[0012] E[|x m (n)| 2 , m = 1, 2, …, M.

[0013] After the transmitting signal undergoes transmitting beamforming and digital-to-analog conversion, it is radiated from the transmitting array into the channel. The transmitting beam is expressed as

[0014] t(n) = w t1 x1(n) + w t2 x2(n) + … + w tM x M (n) + n t (n)

[0015] where represents the transmitting beamforming coefficient corresponding to the m-th transmitting signal, and n t (n) represents the complex additive white Gaussian noise with a mean of 0 and a transmitting signal-to-noise ratio of η t at the transmitter. The receiving beam obtained by the receiver from the channel is expressed as

[0016] r(n) = d(n) + Ht(n)

[0017] where represents the far-field desired signal, Ht(n) represents the self-interference signal, represents the coupling channel between the transmitting and receiving arrays

[0018]

[0019] where represents the channel response between the k-th receiving element and the j-th transmitting element, c represents the channel attenuation factor, D represents the spacing between the transmitting and receiving element pairs, and λ represents the wavelength. The received beam undergoes analog-to-digital conversion and receiving beamforming to obtain M beam signals b1(n), b2(n), …, b M (n), where the m-th beam signal is expressed as

[0020]

[0021] where represents the receiving beamforming coefficient, and n r (n) represents the complex additive white Gaussian noise with a mean of 0 and a transmitting signal-to-noise ratio of ηr Additive white Gaussian noise.

[0022] Assume that the number of reconstructed channels is the same as the number of transmitted signals, and each reconstructed channel contains a linear filter of order P. The reconstructed signal corresponding to the m-th transmitted signal is expressed as

[0023]

[0024] where w cm,p (n) represents the coefficient of the p-th linear filter tap at time n. Denote the reconstruction coefficient as: w cm (n) = [w cm,1 (n), w cm,2 (n), …, w cm,P (n)] T , and within the time range of 1 ≤ i ≤ n, the reconstruction coefficient remains unchanged. Subtract the reconstructed signal from the beamformed signal, and the received signal is expressed as

[0025] y m (n) = b m (n) - (c1(n) + c2(n) + … c M (n))

[0026] The specific steps of step S2 include the following sub-steps:

[0027] S201. Denote the transmit beamforming coefficient vector as w t = [w t1 , w t2 , … w tM T , and the receive beamforming coefficient vector as w r = [w r1 , w r2 , … w rM T . Using the conventional beamforming coefficients, initialize the transmit and receive beamforming coefficient vectors to

[0028]

[0029] and

[0030]

[0031] where P t represents the total transmit power, s t = [s t1 , s t2 , …, s tM T represents the transmit direction vector, and each element is expressed as ​​​

[0032]

[0033] where φ represents the pitch angle, θ represents the azimuth angle, and x t and y t respectively represent the X-axis and Y-axis coordinates of the transmitting array element on the XOY plane. The representation of the receiving direction vector is the same as that of the transmitting direction vector, and its value is the conjugate complex number of the transmitting direction vector.

[0034] S202. Denote the coupling channel matrix as

[0035]

[0036] S203. Taking the minimization of the transmitted residual self-interference and noise power P nt as the optimization objective, use the following optimization problem to simultaneously calculate M transmitting beamforming coefficient vectors

[0037]

[0038]

[0039] ‖‖w t ‖‖ 2 ≤P t

[0040] where g represents the main beam gain, and the value of this variable can be adjusted independently according to needs. M t represents the transmit covariance matrix

[0041]

[0042] where represents the thermal noise power.

[0043] S204. Taking the minimization of the received residual self-interference and noise power P nr as the optimization objective, use the following optimization problem to simultaneously calculate M receiving beamforming coefficient vectors

[0044]

[0045]

[0046] ‖‖w r ‖‖ 2 ≤1

[0047] where M r represents the receive covariance matrix

[0048]

[0049] Alternately iterate the optimization problems in sub-steps S203 and S204, and update the transmit and receive covariance matrices in each iteration. Stop the iteration when both the transmit and receive beamforming coefficient vectors converge.

[0050] The convergence of the transmit beamforming coefficient vector means that: when taking the difference between the transmit beamforming coefficient vectors obtained from two consecutive optimizations, each element in the resulting difference vector is less than a preset threshold.

[0051] The convergence of the receive beamforming coefficient vector means that: when taking the difference between the receive beamforming coefficient vectors obtained from two consecutive optimizations, each element in the resulting difference vector is less than a preset threshold.

[0052] Step S3 includes the following sub-steps:

[0053] S301. According to the least squares criterion, the selection of w cm,p (n) needs to minimize the cumulative residual self-interference and noise power P cm That is,

[0054]

[0055] where 0 < μ ≤ 1 represents the forgetting factor;

[0056] S302. For 1 ≤ i ≤ n time instants, the reconstruction coefficient at time n and the transmit signal vector input to the linear filter at time i are denoted as

[0057] w cm (n) = [w cm,1 (n), w cm,2 (n), …, w cm,P (n)] T

[0058] x m (i) = [x m (i), x m (i + 1), …, x m (i - P + 1)] T

[0059] Within 1 ≤ i ≤ n time instants, the reconstruction coefficient remains unchanged, and the received signal y m (i) is expressed as:

[0060]

[0061] Further expressed as:

[0062] y m (n) = b m (n) - (X m (n)w c1(n) + X m (n)w c2 (n) + … + X m (n)w cM (n))

[0063] where y m (n) represents the m-th received signal vector at the time of 1 ≤ i ≤ n, b m (n) represents the m-th beamforming signal vector at the time of 1 ≤ i ≤ n, X m (n) represents the transmission signal matrix of the m-th input linear filter at the time of 1 ≤ i ≤ n, that is:

[0064] y m (n) = [y m (1), y m (2), …, y m (n)] T

[0065] b m (n) = [b m (1), b m (2), …, b m (n)] T

[0066]

[0067] S303. According to the least squares criterion, at this time, the cumulative residual self-interference and noise power P is minimized cm It is expressed as:

[0068]

[0069] where A(n) = diag(μ n-1 , …, μ, 1) represents the diagonal matrix of the forgetting factor. Derive the residual self-interference and noise power P cm and set the derivative to zero to solve for the m-th reconstruction coefficient as

[0070]

[0071] The present invention has the following advantages: A method for suppressing self-interference of a multi-beam simultaneous transceiver array uses an alternating iteration algorithm in the spatial domain to simultaneously optimize the transmit and receive beamforming coefficients and the least squares criterion in the digital domain to calculate the reconstruction coefficients, effectively suppressing high-power self-interference in the multi-beam simultaneous transceiver array, improving the isolation degree of the transceiver array, and having important guiding significance for realizing wireless communication with large communication capacity, wide coverage range, and low transmission delay in practical engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 It is a schematic flow chart of the present invention;

[0073] Figure 2 It is a simulation diagram of the effective isotropic isolation performance of the transceiver array. Specific implementation manners

[0074] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described in detail below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part rather than all of the embodiments of the present application. The parameters of the embodiments of the present application described and illustrated herein can be configured and set according to various different requirements. Therefore, the detailed description of the embodiments of the present application provided below with reference to the accompanying drawings is not intended to limit the protection scope of the present application, but merely represents the selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0075] As Figure 1 shown, the present invention specifically relates to a self-interference suppression method for a multi-beam simultaneous transceiver array, which simultaneously optimizes the transmit and receive beamforming coefficients through an alternating iteration algorithm in the spatial domain, and calculates the reconstruction coefficients according to the least squares criterion in the digital domain to suppress the self-interference in the multi-beam simultaneous transceiver array step by step, effectively improving the isolation of the transceiver array. The method specifically includes the following steps:

[0076] S1. Mathematically characterize the transmit signal, coupling channel, receive signal, and reconstruction signal of the multi-beam simultaneous transceiver array;

[0077] S2. Optimize the transmit and receive beamforming coefficients using the alternating iteration algorithm in the spatial domain;

[0078] S3. Calculate the reconstruction coefficients of the linear filter according to the least squares criterion in the digital domain;

[0079] S4. Use the transmit and receive beamforming coefficients and the reconstruction coefficients to achieve self-interference suppression in the multi-beam simultaneous transceiver array.

[0080] The specific steps of step S1 include:

[0081] The transmit array in the multi-beam simultaneous transceiver array includes J transmit array elements, and the receive array includes K receive array elements. Denote that there are M transmit signals x1(n), x2(n), …, x M (n) at the transmitter, and the power of the m-th transmit signal is E[|x m (n)| 2 , m = 1, 2, …, M. After the transmit signal passes through transmit beamforming and digital-to-analog conversion, it is radiated from the transmit array into the channel, and the transmit beam is expressed as:

[0082] t(n) = w t1 x1(n) + w t2 x2(n) + … + w tM x M (n) + n t (n)

[0083] where represents the transmit beamforming coefficient corresponding to the m-th transmit signal, and n t (n) represents the complex additive white Gaussian noise with a mean of 0 and a transmit signal-to-noise ratio of η t in the transmitter. The received beam obtained by the receiver from the channel is expressed as

[0084] r(n) = d(n) + Ht(n)

[0085] where represents the far-field desired signal, Ht(n) represents the self-interference signal, represents the coupling channel between the transmit and receive arrays

[0086]

[0087] where represents the channel response between the k-th receive element and the j-th transmit element, c represents the channel attenuation factor, D represents the spacing between the transmit and receive element pairs, and λ represents the wavelength. The received beam undergoes analog-to-digital conversion and receive beamforming to obtain M beam signals b1(n), b2(n), …, b M (n), where the m-th beam signal is expressed as

[0088]

[0089] where represents the receive beamforming coefficient, and n r (n) represents the complex additive white Gaussian noise with a mean of 0 and a transmit signal-to-noise ratio of η r in the receiver.

[0090] It is noted that the number of reconstructed channels is the same as the number of transmit signals, and each reconstructed channel includes a P-th order linear filter. The reconstructed signal corresponding to the m-th transmit signal is expressed as

[0091]

[0092] where w cm,p (n) represents the coefficient of the p-th tap of the linear filter at time n. The reconstructed coefficient is denoted as: w cm (n) = [w cm,1 (n), w cm,2 (n), …, w cm,P (n)] T, within the time period of 1 ≤ i ≤ n, the reconstruction coefficient remains unchanged. Subtract the reconstructed signal from the beam signal, and the received signal is expressed as

[0093] y m (n) = b m (n) - (c1(n) + c2(n) + … c M (n))

[0094] The specific steps of step S2 include the following sub-steps:

[0095] S201. Denote the transmit beamforming coefficient vector as w t = [w t1 , w t2 , … w tM T , and the receive beamforming coefficient vector as w r = [w r1 , w r2 , … w rM T . Using the conventional beamforming coefficients, initialize the transmit and receive beamforming coefficient vectors respectively as

[0096]

[0097]

[0098] where P t represents the total transmit power, s t = [s t1 , s t2 , …, s tM T represents the transmit direction vector, and each element is expressed as

[0099]

[0100] where φ represents the elevation angle, θ represents the azimuth angle, x t and y t respectively represent the X-axis and Y-axis coordinates of the transmit array element on the XOY plane. The representation of the receive direction vector is the same as that of the transmit direction vector, and its value is the conjugate complex number of the transmit direction vector.

[0101] S202. Denote the coupling channel matrix as

[0102]

[0103] S203. To minimize the transmit residual self-interference and noise power P nt ​​​Taking the following as the optimization objective, simultaneously calculate M transmit beamforming coefficient vectors by using the following optimization problem

[0104]

[0105]

[0106] ‖‖w t ‖‖ 2 ≤P t

[0107] where g represents the main beam gain, and the value of this variable can be adjusted independently as needed. M t represents the transmit covariance matrix

[0108]

[0109] where represents the thermal noise power.

[0110] S204. Taking the minimization of the received residual self-interference and noise power P nr as the optimization objective, simultaneously calculate M receive beamforming coefficient vectors by using the following optimization problem

[0111]

[0112]

[0113] ‖‖w r ‖‖ 2 ≤1

[0114] where M r represents the receive covariance matrix

[0115]

[0116] S205. Alternately iterate the optimization problems in sub-steps S203 and S204, and update the transmit and receive covariance matrices in each iteration. Stop the iteration when both the transmit and receive beamforming coefficient vectors converge.

[0117] The step S3 includes the following sub-steps:

[0118] S301. According to the least squares criterion, the selection of w cm,p (n) needs to minimize the cumulative residual self-interference and noise power P cm i.e.,

[0119]

[0120] where 0 < μ ≤ 1 represents the forgetting factor;

[0121] At the time when \(1\leq i\leq n\), the reconstruction coefficient at time \(n\) and the transmitted signal vector input to the linear filter at time \(i\) are denoted as

[0122] w cm (n)=[w cm,1 (n),w cm,2 (n),…,w cm,P (n)] T

[0123] x m (i)=[x m (i),x m (i + 1),…,x m (i - P + 1)] T

[0124] At the time when \(1\leq i\leq n\), the reconstruction coefficient remains unchanged, and the received signal \(y\) m (i) is expressed as:

[0125]

[0126] Further expressed as:

[0127] y m (n)=b m (n)-(X m (n)w c1 (n)+X m (n)w c2 (n)+…+X m (n)w cM (n))

[0128] where \(y\) m (n) represents the \(m\)-th received signal vector at the time when \(1\leq i\leq n\), \(b\) m (n) represents the \(m\)-th beamforming signal vector at the time when \(1\leq i\leq n\), \(X\) m (n) represents the transmitted signal matrix of the \(m\)-th input linear filter at the time when \(1\leq i\leq n\), that is:

[0129] y m (n)=[y m (1),y m (2),…,y m (n)] T

[0130] b m (n)=[b m (1),b m (2),…,b m (n)] T

[0131]

[0132] S303. According to the least squares criterion, at this time, the cumulative residual self-interference and noise power P is minimized cm It is expressed as:

[0133]

[0134] where A(n) = diag(μ n-1 , …, μ, 1) represents a diagonal matrix of forgetting factors, for the residual self-interference and noise power P cm Derive and set the derivative to zero to solve for the m-th reconstruction coefficient as

[0135]

[0136] The said step S4 includes the following sub-steps:

[0137] S401. Substitute the transmit and receive beamforming coefficient vectors obtained in step S205 into sub-step S102 to obtain the transmit beam;

[0138] S402. Substitute the reconstruction coefficients obtained in step S3 into sub-step S104 to obtain the reconstructed signal;

[0139] S403. According to the self-interference suppression scenario of the multi-beam simultaneous transceiver array constructed in step S1, obtain the received signal, and the self-interference in the received signal is suppressed.

[0140] Perform performance simulation on the proposed self-interference suppression method for the multi-beam simultaneous transceiver array. The transceiver array plane of the multi-beam simultaneous transceiver array is located on the XOY plane of the XYZ coordinate system, and the elevation angle and azimuth angle are respectively the angles between the transmit beam and the receive beam and the X-axis and Z-axis. The simulation parameters are set as follows:

[0141]

[0142]

[0143] The simulation results are as Figure 2 shown. It can be found that when directly using the conventional beamforming and least squares criterion in the self-interference suppression method of the single-beam simultaneous transceiver array, the effective isotropic isolation degree of the transceiver array is only 105 dB. Using the proposed self-interference suppression method for the multi-beam simultaneous transceiver array in this patent, the effective isotropic isolation degree of the transceiver array reaches 173 dB. The proposed self-interference suppression method for the multi-beam simultaneous transceiver array in this patent has a much higher effective isotropic isolation degree of the transceiver array than directly using the self-interference suppression method of the single-beam simultaneous transceiver array, verifying that this method has significant self-interference suppression performance advantages.

[0144] In view of the problem that existing research does not cover the self-interference suppression method for multi-beam simultaneous transceiver arrays, and directly using the self-interference suppression method of single-beam simultaneous transceiver arrays in multi-beam simultaneous transceiver arrays will result in poor self-interference suppression performance, the self-interference suppression method for multi-beam simultaneous transceiver arrays proposed by the present invention can greatly suppress the self-interference in multi-beam simultaneous transceiver arrays, improve the isolation degree of the transceiver array, and has important guiding significance for realizing wireless communication with large communication capacity, wide coverage range, and low transmission delay in practical engineering.

[0145] The above are only the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications, and environments, and can be changed within the scope of the inventive concept described herein through the above teachings or the techniques or knowledge in related fields. And any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention shall fall within the protection scope of the appended claims of the present invention.

Claims

1. A method for suppressing self-interference of a multi-beam simultaneous transceiver array, characterized in that: It includes the following steps: S1. Construct the self-interference suppression scenario of the multi-beam simultaneous transceiver array: The transmitted signal is radiated into the channel from the transmitting array surface after transmitting beamforming and digital-to-analog conversion, forming a transmitting beam; When the receiver receives the signal, the received beam is subjected to analog-to-digital conversion and receiving beamforming to obtain a beam-wave signal, and the received signal is obtained by subtracting the signal reconstructed locally using a linear filter from the beam-wave signal; S2. Optimize the transmitting and receiving beamforming coefficients in the spatial domain using the alternating iteration algorithm; S3. Calculate the reconstruction coefficients of the linear filter according to the least squares criterion in the digital domain; S4. Implement self-interference suppression in the multi-beam simultaneous transceiver array using the transmitting and receiving beamforming coefficients and the reconstruction coefficients.

2. The multi-beam simultaneous transceiver array self-interference suppression method according to claim 1, wherein: The step S1 includes: S101. Assume that the transmitting array in the multi-beam simultaneous transceiver array includes J transmitting array elements, and the receiving array includes K receiving array elements; S102. The transmitted signal is radiated into the channel from the transmitting array after transmitting beamforming and digital-to-analog conversion, forming a transmitting beam; It is noted that there are M transmitted signals x1(n), x2(n), …, x M (n) at the transmitter, and the power of the m-th transmitted signal is: E[|x m (n)| 2 , m = 1, 2, …, M; The transmitted signal is radiated into the channel from the transmitting array after transmitting beamforming and digital-to-analog conversion, and the transmitting beam is expressed as: t(n) = w t1 x1(n) + w t2 x2(n) + … + w tM x M (n) + n t (n) Among them Denote the transmit beamforming coefficient corresponding to the m-th transmit signal, n t (n) represents the complex additive white Gaussian noise with a mean of 0 and a transmit signal-to-noise ratio of η in the transmitter t ; S103. The receiver obtains the received beam from the signal through K receiving array elements, and the received beam is subjected to analog-to-digital conversion and receiving beamforming to obtain a beam-wave signal: The received beam obtained by the receiver from the channel is expressed as: r(n) = d(n) + Ht(n) Among them, denotes the far-field desired signal, and Ht(n) denotes the self-interference signal. denotes the coupling channel between the transceiver arrays: where represents the channel response between the k-th receiving array element and the j-th transmitting array element, c represents the channel attenuation factor, D represents the distance between the transceiver array element pair, and λ represents the wavelength; The received beam undergoes analog-to-digital conversion and receive beamforming to obtain M beam signals b1(n), b2(n), …, b M (n), where the m-th beam signal is expressed as: wherein represents the received beamforming coefficient, and n r (n) represents the complex additive white Gaussian noise with a mean of 0 and a transmit signal-to-noise ratio of η r in the receiver; S104. Reconstruct the transmitted signal in the receiver: It is noted that the number of reconstructed channels is the same as the number of transmitted signals, each reconstructed channel includes a P-order linear filter, and the reconstructed signal corresponding to the m-th transmitted signal is expressed as: where w cm,p (n) represents the coefficient of the p-th tap of the linear filter at time n, and the reconstruction coefficient is denoted as: w cm (n) = [w cm,1 (n), w cm,2 (n), …, w cm,P (n)] T , within the time of 1 ≤ i ≤ n, the reconstruction coefficient remains unchanged; S105. Subtract the reconstructed signal from the beam-wave signal to obtain the received signal expressed as y m y(n) = b m y(n) - (c1(n) + c2(n) + … c M (n)).

3. A method for suppressing self-interference of a multi-beam simultaneous transceiver array according to claim 2, characterized in that: The step S2 includes the following sub-steps: S201. Denote the transmit beamforming coefficient vector as w t = [w t1 , w t2 , … w tM T , and the receive beamforming coefficient vector as w r = [w r1 , w r2 , … w rM T ;​​ Initialize the transmitting beamforming coefficient vector as Initialize the receiving beamforming coefficient vector as where P t represents the total transmission power, s t = [s t1 , s t2 , …, s tM T represents the transmission direction vector, and each element is expressed as​ where φ represents the pitch angle, θ represents the azimuth angle, and x t and y t respectively represent the X-axis and Y-axis coordinates of the transmitting array element on the XOY plane; the representation of the receiving direction vector is the same as that of the transmitting direction vector, and its value is the conjugate complex number of the transmitting direction vector; S202. Record the coupled channel matrix Denoted as S203. Minimize the transmit residual self-interference and noise power P nt For the optimization objective, use the following optimization problem to simultaneously calculate M transmit beamforming coefficient vectors where g represents the main beam gain, and M t represents the transmit covariance matrix wherein represents the thermal noise power; S204. Minimize the received residual self-interference and noise power P nr As the optimization objective, use the following optimization problem to simultaneously calculate M received beamforming coefficient vectors where M r represents the received covariance matrix S205. Alternately iterate the optimization problems in sub-steps S203 and S204, and update the transmitting and receiving covariance matrices in each iteration. When both the transmitting and receiving beamforming coefficient vectors converge, the iteration stops; The convergence of the transmitting beamforming coefficient vector means that: when the difference between the transmitting beamforming coefficient vectors obtained by two consecutive optimizations is calculated, each element in the obtained difference vector is less than the preset threshold; The convergence of the receiving beamforming coefficient vector means that: when the difference between the receiving beamforming coefficient vectors obtained by two consecutive optimizations is calculated, each element in the obtained difference vector is less than the preset threshold.

4. A method for suppressing self-interference of a multi-beam simultaneous transceiver array according to claim 3, characterized in that: The step S3 includes the following sub-steps: S301. According to the least squares criterion, the selection of w cm,p (n) needs to minimize the cumulative residual self-interference and noise power P cm to be minimized, that is where 0 < μ ≤ 1 represents the forgetting factor; S302. For the time within 1 ≤ i ≤ n, denote the reconstruction coefficient at time n and the vector of the transmitted signal input to the linear filter at time i as w cm (n) = [w cm,1 (n), w cm,2 (n), …, w cm,P (n)] T x m (i) = [x m (i), x m (i + 1), …, x m (i - P + 1)] T During the time when 1 ≤ i ≤ n, the reconstruction coefficient remains unchanged, and the received signal y m (i) is expressed as: Further expressed as: y m (n) = b m (n) - (X m (n)w c1 (n) + X m (n)w c2 (n) + … + X m (n)w cM (n)) where y m (n) represents the m-th received signal vector at the time of 1 ≤ i ≤ n, b m (n) represents the m-th beam wave signal vector at the time of 1 ≤ i ≤ n, X m (n) represents the transmission signal matrix of the m-th input linear filter at the time of 1 ≤ i ≤ n, that is: y m (n) = [y m (1), y m (2), …, y m (n)] T b m b(n) = [b m (1), b m (2), …, b m (n)] T S303. According to the least squares criterion, the cumulative residual self-interference and noise power P is minimized at this time cm It is expressed as: where \(A(n)=\text{diag}(\mu n-1 ,\ldots,\mu,1)\) represents the diagonal matrix of the forgetting factor, for the residual self-interference and noise power \(P cm Take the derivative and set the derivative to zero, and solve for the \(m\)-th reconstruction coefficient as 5. A method for suppressing self-interference of a multi-beam simultaneous transceiver array according to claim 4, characterized in that: The step S4 includes the following sub-steps: S401. Substitute the transmitting and receiving beamforming coefficient vectors obtained in step S205 into sub-step S102 to obtain the transmitting beam; S402. Substitute the reconstruction coefficients obtained in step S3 into sub-step S104 to obtain the reconstructed signal; S403. Obtain a received signal according to the self-interference suppression scenario of the multi-beam simultaneous transceiver array constructed in step S1, where the self-interference in the received signal is suppressed.

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