Multi-functional integrated platform co-location interference suppression method

Abstract

The invention discloses a co-location interference suppression method for a multifunctional integrated platform. The co-location interference suppression method comprises the following steps: S1, establishing a joint receiving application scene of a main receiving antenna and an auxiliary receiving antenna in the presence of a plurality of interference antennas; s2, constructing a multivariable optimization problem based on the position of the auxiliary receiving antenna; s3, deducing a closed expression of residual interference power and an auxiliary receiving antenna position in a double-interference scene through a time domain convolution and frequency domain transformation method; and S4, carrying out global search on the position of the auxiliary receiving antenna by adopting a genetic algorithm, a particle swarm optimization algorithm and a locust optimization algorithm to realize the minimization of residual interference power. In order to solve the problem of co-location interference in multifunctional integrated common platform equipment, the interference suppression method based on the auxiliary receiving antenna, provided by the invention, suppresses co-location interference existing in a system so as to ensure normal communication of a multifunctional integrated common platform.

Description

Technical Field

[0001] The present invention belongs to the field of multi-device electromagnetic wave mutual interference suppression, and particularly relates to a method for suppressing co-site interference of a multi-functional integrated platform. Background Art

[0002] With the increasing scarcity of the spectrum, advanced communication methods with higher spectral efficiency are required. In multi-radio systems (such as airplanes, ships, and vehicles), transmitters and receivers share overlapping frequency bands and operate simultaneously. However, insufficient transceiver isolation introduces strong co-site radio frequency interference from local transmitters. This interference saturates low-noise amplifiers and analog-to-digital converters, thereby blocking the reception of remote signals of interest. Co-site interference cancellation techniques based on auxiliary receiving antennas use the auxiliary receiving antennas to receive interference signals for cancellation. However, most existing methods fix the positions of the auxiliary receiving antennas and rely on additional radio frequency circuits to compensate for path differences, increasing the hardware complexity and cost.

[0003] In addition, current research mainly focuses on a single interference scenario, with insufficient analysis of the signal coupling characteristics under the condition of coexistence of multiple interferences. Moreover, traditional optimization methods are prone to falling into local optima and it is difficult to achieve the spatio-temporal joint suppression of interference signals. Therefore, how to achieve efficient cancellation in multi-interference scenarios through dynamic optimization of the positions of auxiliary receiving antennas while reducing the hardware overhead has become a key challenge for improving the robustness of the system. 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 realizing co-site interference suppression to ensure the normal communication of a multi-functional integrated communication system by suppressing co-site interference.

[0005] The purpose of the present invention is realized through the following technical solutions: A method for suppressing co-site interference of a multi-functional integrated platform, comprising the following steps:

[0006] S1. In the case of multiple interfering antennas, establish a joint receiving application scenario for the main receiving antenna and the auxiliary receiving antenna;

[0007] S2. Construct a multi-variable optimization problem based on the position of the auxiliary receiving antenna;

[0008] S3. Through time-domain convolution and frequency-domain transformation methods, derive a closed-form expression of the residual interference power and the position of the auxiliary receiving antenna in a double-interference scenario;

[0009] S4. Use genetic algorithms, particle swarm algorithms, and locust optimization algorithms to globally search for the position of the auxiliary receiving antenna to minimize the residual interference power.

[0010] Further, the step S1 includes:

[0011] S101. Application scenario of the setting method: Assume that the scenario includes a transmitter at the far end, and a local receiver and multiple interferers at the near end; the local receiver includes two receivers at the near end;

[0012] The transmitter transmits the desired signal through the transmitting antenna; the interferer at the near end transmits a high-power interference signal through the interference antenna;

[0013] The two receivers at the near end are the main receiver and the auxiliary receiver respectively; the main receiver receives signals through the main receiving antenna, and the auxiliary receiver receives signals through the auxiliary receiving antenna. After the auxiliary receiving antenna receives the signal, it is directly transmitted to the main receiver through a wired connection to achieve co-located interference suppression, so that the main receiver can correctly receive the signal from the far-end transmitter;

[0014] S102. Assume that the positions of the main receiver, interferer, and transmitter do not change within each period, then only change the position of the auxiliary receiver to minimize the power of the residual interference signal. Within the period T, first find the optimal position of the auxiliary receiver at time a, and then perform data transmission during the remaining time.

[0015] The step S2 includes:

[0016] S201. The signals received by the main receiving antenna and the auxiliary receiving antenna are expressed as:

[0017]

[0018] where, is the convolution operation, I i (t) is the transmission signal of the i-th interferer, u(t) is the expected signal sent from the transmitter to the main receiver, n M (t) and n A (t) are both additive white Gaussian noise, h MS (t), and h AS (t) represent the channels between the main receiving antenna, the auxiliary receiving antenna, the i-th interference antenna, and the transmitting antenna respectively;

[0019] Assume that there is line-of-sight (LOS) transmission between the receiver and the transmitter or interferer, and all channels conform to the free space path loss model, expressed in dB as:

[0020] h = 32.45 + 20lgf + 20lgd

[0021] where f is the sampling frequency and d is the propagation distance;

[0022] Typically, the interfering antenna, the main receiving antenna, and the auxiliary receiving antenna are in a relatively close area, and there is always a line-of-sight path. The power of the direct interference is much higher than that of the non-direct interference signal (i.e., the reflected interference signal). The non-direct interference signal can be converted by analog-to-digital conversion and interference suppression can be performed in the digital domain. Considering the direct interference signal, taking the channel between the interfering antenna and the main receiving antenna as an example, it can be expressed as:

[0023]

[0024] where δ(·) is the Dirichlet function, τ is the transmission delay, c is the speed of light, represents the distance between the main receiver and the i-th interferer; where ||·|| is the 2-norm; d M represents the coordinate position of the main receiver, represents the coordinate position of the i-th interferer;

[0025] Similarly, the channel between the transmitting antenna and the main receiving antenna is:

[0026]

[0027] d MS represents the distance between the transmitter and the main receiver; d MS = ||d M - d S || 2 ; d S represents the coordinate position of the transmitter;

[0028] The channel between the i-th interfering antenna and the auxiliary receiving antenna is:

[0029]

[0030] represents the distance between the auxiliary receiver and the i-th interferer; d A represents the coordinate position of the auxiliary receiver;

[0031] The channel between the transmitting antenna and the auxiliary receiving antenna is:

[0032]

[0033] d AS represents the distance between the transmitter and the auxiliary receiver; d AS = ||d A - d S || 2 ;

[0034] S202. The signal received by the auxiliary receiving antenna is superimposed on the signal received by the main receiving antenna. At the same time, since all antennas have receiving gain, the signal after the local receiver, i.e. the main receiver and the auxiliary receiver, are superimposed is:

[0035] y(t)=ρ M r(t)+ρ A r A (t)

[0036] Among them, ρ M is the receiving gain of the main receiver antenna, ρ A is the receiving gain of the auxiliary receiver antenna;

[0037] In one cycle, the co-site interference suppression process is first performed; at this time, the remote transmitter does not transmit a signal, and the signals received by the main receiving antenna and the auxiliary receiving antenna are canceled by several interference signals of the channel, which is expressed as:

[0038]

[0039] Minimizing the residual SI signal power received by the local transceiver is expressed as:

[0040]

[0041] The step S3 comprises:

[0042] S301.P r Transform to the frequency domain:

[0043]

[0044] Among them, f H is the highest frequency of the interference signal, f L is the lowest frequency. Assume that the interference signal, additive Gaussian noise n M (t) and additive Gaussian noise n A (t) is not related. The superscript * indicates conjugation;

[0045] Further expansion yields:

[0046]

[0047] in,

[0048]

[0049] Y(t), N(t), R M (t), R A (t) is the intermediate variable;

[0050] Then, P rCan be re-expressed as:

[0051]

[0052] S302. Further expand P r to the frequency domain:

[0053]

[0054] In addition,

[0055]

[0056] where r is the correlation coefficient between the two interfering signals, and I1(f) and I2(f) are the power spectral densities of the two interfering signals respectively; represents the phase value of the channel between the primary receiver and interfering source 1, represents the phase value of the channel between the primary receiver and interfering source 2, represents the phase value of the channel between the auxiliary receiver and interfering source 1, represents the phase value of the channel between the auxiliary receiver and interfering source 2;

[0057] Assume that I1(f) and I2(f) are close to constants within one period, and further simplify the Pr expression:

[0058]

[0059] where sinc(x) = sin(x) / x, and B represents the bandwidth of the signal.

[0060] The step S4 includes:

[0061] S401. Use the co-located interference suppression method based on the genetic algorithm, the co-located interference suppression method based on the particle swarm algorithm, and the co-located interference suppression method based on the locust algorithm for optimization and solution to find the coordinate point with the minimum residual interference power, which is the optimal position of the auxiliary receiving antenna.

[0062] The beneficial effect of the present invention is that for the co-located interference suppression problem in the multi-functional integrated platform system, the co-located interference suppression method provided by the present invention suppresses the co-located interference existing in the system to ensure the normal communication of the multi-functional integrated platform system. Description of the Drawings

[0063] Figure 1 is the flowchart of the method of the present invention;

[0064] Figure 2 is a schematic diagram of the principle of the communication system model including the interference antenna, the primary receiving antenna, the auxiliary receiving antenna, and the transmitting antenna;

[0065] Figure 3 Schematic diagram of the optimal position of the auxiliary receiving antenna;

[0066] Figure 4 Schematic diagram of the relationship between the interference correlation coefficient and the residual interference power / interference suppression ratio. Specific implementation manners

[0067] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0068] As Figure 1 shown, a method for suppressing co-site interference of a multi-functional integrated platform includes the following steps:

[0069] S1. Establish a joint reception application scenario of the main receiving antenna and the auxiliary receiving antenna in the presence of multiple interfering antennas;

[0070] S2. Construct a multi-variable optimization problem based on the position of the auxiliary receiving antenna;

[0071] S3. Through time-domain convolution and frequency-domain transformation methods, derive a closed-form expression of the residual interference power and the position of the auxiliary receiving antenna in a two-interference scenario;

[0072] S4. Use genetic algorithm, particle swarm algorithm and locust optimization algorithm to globally search for the position of the auxiliary receiving antenna to minimize the residual interference power.

[0073] Among them, the steps of S1 include:

[0074] S101. Set the application scenario of the method: assume that the scenario includes a transmitter at the far end, and a local receiver and multiple interferers at the near end; the local receiver includes two receivers at the near end;

[0075] The transmitter transmits the desired signal through the transmitting antenna; the near-end interferer transmits a high-power interference signal through the interfering antenna;

[0076] The two receivers at the near end are the main receiver and the auxiliary receiver respectively; the main receiver receives the signal through the main receiving antenna, and the auxiliary receiver receives the signal through the auxiliary receiving antenna. After the auxiliary receiving antenna receives the signal, it is directly transmitted to the main receiver through a wired connection to achieve co-site interference suppression, so that the main receiver can correctly receive the signal from the far-end transmitter;

[0077] S102. Assume that the positions of the main receiver, the interferer and the transmitter do not change in each period, then only change the position of the auxiliary receiver to minimize the power of the residual interference signal. In the period T, first find the optimal position of the auxiliary receiver within the time a, and then perform data transmission in the remaining time.

[0078] The steps of S2 include:

[0079] S201. The signals received by the main receiving antenna and the auxiliary receiving antenna at the proximal end can be expressed as:

[0080]

[0081] where, is the convolution operation, I i (t) is the transmission signal of the i-th jammer, u(t) is the expected signal sent from the remote transceiver to the local transceiver, n M (t) and n A (t) are both additive white Gaussian noise, h MS (t), and h AS (t) represent the channels between the main receiving antenna, the auxiliary receiving antenna, the i-th and the transmitting antenna respectively.

[0082] Assume that there is a line-of-sight (LOS) transmission between the receiver and the transmitter or jammer, and all channels conform to the free space path loss model, expressed in dB as:

[0083] h = 32.45 + 20lgf + 20lgd

[0084] where f is the sampling frequency and d is the propagation distance. For example, represents the distance between the receiver and the i-th jammer. where ||·|| is the 2-norm. d M represents the coordinate position of the main receiver, represents the coordinate position of the i-th jammer;

[0085] Generally, the interfering antenna, the main receiving antenna and the auxiliary receiving antenna are respectively in a relatively close area, and there is always a line-of-sight path. The power of the direct interference is much higher than that of the non-direct interference signal (i.e., the reflected interference signal). The non-direct interference signal can be converted by analog-to-digital conversion and interference suppression can be carried out in the digital domain. Considering the direct interference signal, taking the channel between the interfering antenna and the main receiving antenna as an example, it can be expressed as:

[0086]

[0087] where, δ(·) is the Dirichlet function, τ is the transmission delay, and c is the speed of light.

[0088] S202. Superimpose the signal received by the auxiliary receiving antenna on the signal received by the main receiving antenna. At the same time, due to the receiving gain of all antennas, the signal received by the local transceiver is:

[0089] y(t) = ρ M r(t) + ρ A r A (t)

[0090] where ρ M is the receiving gain of the main antenna, and ρ A is the receiving gain of the auxiliary antenna.

[0091] During one period, the co-site interference suppression process is first performed. At this time, the remote transmitter does not transmit signals, and the signals received by the main receiving antenna and the auxiliary receiving antenna are the cancellation of several interference signals passing through the channel, which can be expressed as:

[0092]

[0093] Minimizing the power of the remaining SI signal received by the local transceiver can be expressed as:

[0094]

[0095] The steps of S3 include:

[0096] S301. Transform P r to the frequency domain:

[0097]

[0098] where f H is the highest frequency of the interference signal, and f L is the lowest frequency. And it is assumed that the interference signal, additive Gaussian noise n M (t) and additive Gaussian noise n A (t) are uncorrelated.

[0099] Further expansion gives:

[0100]

[0101] where,

[0102]

[0103] Then, P r can be re-expressed as:

[0104]

[0105] S302. Further expand P r to the frequency domain:

[0106]

[0107] In addition,

[0108]

[0109] Among them, for any two interfering signals, r is the correlation coefficient between the two interfering signals, and I1(f) and I2(f) are the power spectral densities of the two interfering signals respectively; represents the phase value of the channel between the primary receiver and interfering source 1, represents the phase value of the channel between the primary receiver and interfering source 2, represents the phase value of the channel between the auxiliary receiver and interfering source 1, represents the phase value of the channel between the auxiliary receiver and interfering source 2;

[0110] Assume that I1(f) and I2(f) are close to constants within one period, and further simplify the Pr expression:

[0111]

[0112] Among them, sinc(x) = sin(x) / x, and B represents the bandwidth of the signal.

[0113] The steps of S4 include:

[0114] According to the obtained P r expression, at the same time, use three algorithms, namely genetic algorithm, particle swarm algorithm or locust algorithm, for optimization and solution. Take P r as the objective function and minimize the objective function; P r is an expression related to the position of the auxiliary receiver. The output of the algorithm is the coordinate position of the auxiliary receiver. Compare the three algorithms to find the coordinate point with the minimum residual interference power respectively. Among them, the point with the minimum residual interference power is the optimal position of the auxiliary receiving antenna. After finding the coordinate point with the minimum residual interference power, the optimal position of the auxiliary receiving antenna is obtained.

[0115] The beneficial effect of the present invention is: aiming at the co-location interference suppression problem in the multi-functional integrated platform system, the co-location interference suppression method provided by the present invention suppresses the co-location interference existing in the system to ensure the normal communication of the multi-functional integrated platform system.

[0116] In the embodiment of the present application, according to the method of the present invention, a communication system model is constructed based on the simultaneous presence of one remote transmitting antenna, two proximal receiving antennas, namely the primary receiving antenna and the auxiliary receiving antenna, and several proximal interfering antennas, as Figure 2 shown. Simulation verification is carried out on the MATLAB tool, and the simulation parameters are shown in the following table:

[0117]

[0118]

[0119] Figure 3 Optimize and solve through the co-site interference suppression method based on the genetic algorithm, the co-site interference suppression method based on the particle swarm algorithm, and the co-site interference suppression method based on the locust algorithm. Then compare the optimal solutions of the three algorithms, find the value with the minimum residual interference power and its corresponding coordinate points. Finally, it is found that the co-site interference suppression method based on the locust algorithm has the best effect. The positions of the main receiving antenna and the interfering antenna are marked in the figure, and especially the best position of the auxiliary receiving antenna is highlighted.

[0120] Figure 4 The relationship between the residual interference power and the interference suppression ratio is plotted under different correlation coefficients of two interfering signals. The simulation results show that a lower correlation coefficient can significantly reduce the residual interference power, thus generating a higher interference suppression ratio. Compared with the co-site interference suppression method based on the particle swarm algorithm and the co-site interference suppression method based on the locust algorithm, the performance of the co-site interference suppression method based on the genetic algorithm is the worst, which may be due to the optimization process falling into a local optimum, while the performance of the co-site interference suppression method based on the particle swarm algorithm and the co-site interference suppression method based on the locust algorithm is comparable, reaching a residual interference power of -48.78 dBm and an interference suppression ratio of 50.93 dB.

[0121] The present invention has been described and proven in detail here, enabling those skilled in the art to understand and apply the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. As long as the changes and modifications made by those skilled in the art do not depart from the spirit and scope of the present invention, they should all be within the protection scope of the appended claims of the present invention.

Claims

1. A method for suppressing co-site interference of a multifunctional integrated platform, comprising the following steps: S1. In the presence of multiple interfering antennas, establish a joint reception application scenario of the main receiving antenna and the auxiliary receiving antenna; S2. Construct a multivariable optimization problem based on the auxiliary receiving antenna position; S3. Through the time domain convolution and frequency domain transformation method, the closed-form expression of the residual interference power and the auxiliary receiving antenna position in the dual interference scenario is derived; S4. Genetic algorithm, particle swarm algorithm and locust optimization algorithm are used to perform a global search for the position of the auxiliary receiving antenna to minimize the residual interference power.

2. The method for suppressing co-site interference of a multifunctional integrated platform according to claim 1, characterized in that: The step S1 comprises: S101. Setting the application scenario of the method: Assume that the scenario includes a remote transmitter, a local receiver at a near end, and a plurality of jammers; the local receiver includes two near-end receivers; The transmitter transmits the desired signal through the transmitting antenna; the near-end jammer transmits a high-power jamming signal through the jamming antenna; Two near-end receivers are a main receiver and an auxiliary receiver. The main receiver receives signals through a main receiving antenna, and the auxiliary receiver receives signals through an auxiliary receiving antenna. After the auxiliary receiving antenna receives the signal, it is directly transmitted to the main receiver through a wired connection to achieve co-site interference suppression, so that the main receiver can correctly receive the signal of the remote transmitter. S102. Assuming that the positions of the main receiver, jammer and transmitter do not change in each cycle, only the position of the auxiliary receiver is changed to minimize the power of the residual interference signal. Within cycle T, the optimal position of the auxiliary receiver is first found within time a, and then data transmission is performed in the remaining time.

3. The method for suppressing co-site interference of a multifunctional integrated platform according to claim 1, characterized in that: The step S2 comprises: S201. The signals received by the main receiving antenna and the auxiliary receiving antenna are expressed as: in, is the convolution operation, I i (t) is the transmission signal of the ith jammer, u(t) is the expected signal sent from the transmitter to the primary receiver, n M (t) and n A (t) are all additive white Gaussian noise, h MS (t), and h AS (t) represent the channels between the main receiving antenna, the auxiliary receiving antenna, the i-th interference antenna and the transmitting antenna respectively; Assuming there is line of sight between the local receiver and the transmitter or jammer, and all channels conform to the free space path loss model, expressed in dB as: h=32.45+20lgf+20lgd Where f is the sampling frequency and d is the propagation distance; For the channel between the i-th interference antenna and the main receiving antenna, it is expressed as: where δ(·) is the Dirichlet function, τ is the transmission delay, c is the speed of light, represents the distance between the main receiver and the i-th jammer; where ||·|| is the 2-norm; d M Indicates the coordinate position of the main receiver, represents the coordinate position of the i-th jammer; Similarly, the channel between the transmitting antenna and the main receiving antenna is: d MS Indicates the distance between the transmitter and the main receiver; d MS =||d M -d S || 2 ;d S Indicates the coordinate position of the transmitter; The channel between the i-th interference antenna and the auxiliary receiving antenna is: represents the distance between the auxiliary receiver and the i-th jammer; d A Indicates the coordinate position of the auxiliary receiver; The channel between the transmitting antenna and the auxiliary receiving antenna is: d AS Indicates the distance between the transmitter and the auxiliary receiver; d AS =||d A -d S || 2 ; S202. The signal received by the auxiliary receiving antenna is superimposed on the signal received by the main receiving antenna. At the same time, since all antennas have receiving gain, the signal after the local receiver, that is, the main receiver and the auxiliary receiver are superimposed is: y(t)=ρ M r(t)+ρ A r A (t) Among them, ρ M is the receiving gain of the main receiver antenna, ρ A is the receiving gain of the auxiliary receiver antenna; In one cycle, the co-site interference suppression process is first performed; at this time, the remote transmitter does not transmit a signal, and the signals received by the main receiving antenna and the auxiliary receiving antenna are canceled by several interference signals of the channel, which is expressed as: Minimizing the residual SI signal power received by the local receiver is expressed as:

4. The method for suppressing co-site interference of a multifunctional integrated platform according to claim 1, characterized in that: The step S3 comprises: S301.P r Transform to the frequency domain: Among them, f H is the highest frequency of the interference signal, f L is the lowest frequency, and assuming that the interference signal, additive Gaussian noise n M (t) and additive Gaussian noise n A (t) unrelated; the superscript * indicates conjugation; Further expanded to: in, Y(t), N(t), R M (t), R A (t) is the intermediate variable; Then, P r is reformulated as: S302. Further P r Expanding to the frequency domain: In addition, define the following intermediate variables: Where r is the correlation coefficient between the two interference signals, I1(f) and I2(f) are the power spectral densities of the two interference signals respectively; represents the phase value of the channel between the main receiver and the interference source 1, represents the phase value of the channel between the main receiver and the interference source 2, represents the phase value of the channel between the auxiliary receiver and the interference source 1, Represents the phase value of the channel between the auxiliary receiver and the interference source 2; Assuming that I1(f) and I2(f) are close to constants within a period, further calculation of P r The expression is simplified: Wherein, sinc(x)=sin(x) / x, and B represents the bandwidth of the signal.

5. The method for suppressing co-site interference of a multifunctional integrated platform according to claim 1, characterized in that: The step S4 comprises: According to the obtained P r Expression, using genetic algorithm, particle swarm algorithm or locust algorithm to optimize and solve, with P r As the objective function, minimize the objective function; P r It is an expression about the position of the auxiliary receiver. The algorithm output is the coordinate position of the auxiliary receiver. The three algorithms are compared to find the coordinate point with the minimum residual interference power. The point with the minimum residual interference power is the optimal position of the auxiliary receiving antenna. After finding the coordinate point with the minimum residual interference power, the optimal position of the auxiliary receiving antenna is obtained.

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