An antenna array interference suppression method based on pattern reconstruction and cancellation

Abstract

An antenna array interference suppression method based on pattern reconstruction and cancellation relates to the technical field of wireless communication anti-interference. The invention aims to solve the problem that the suppression capability of the existing airspace anti-interference system is fixed and the normal demodulation of communication signals cannot be guaranteed in a strong interference environment. The invention proposes an antenna array interference suppression method based on pattern reconstruction and cancellation. Without adding any hardware resources used by the antenna array, the invention makes full use of processor computing resources. On the basis of the original receiver, the phase of the received data of each antenna component is additionally adjusted to complete the pattern reconstruction. The processed data after the reconstructed pattern is cancelled with the original processed data to form a secondary superposition between the signals. The invention is suitable for interference suppression occasions of wireless communications.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless communication anti-interference, and specifically relates to an antenna array interference suppression technology based on pattern reconstruction and cancellation. Background Art

[0002] Regardless of whether it is a dedicated or commercial communication system, it is inevitably affected by various types of interference. In the field of anti-interference technology, time-frequency domain anti-interference technologies such as burst communication, frequency hopping / spread spectrum, etc. have been developed. With the maturity of 4G systems, the commercialization of 5G systems, and the pre-research of 6G systems, antenna arrays have become a common means to improve capacity and reliability in communication systems. Antenna arrays provide spatial resources for anti-interference technology, and based on this, various spatial anti-interference methods such as beamforming and adaptive nulling have been developed, that is, by adjusting the pattern of the antenna array to align the main lobe with the arrival direction of the communication signal, and the nulls towards the interference direction, so as to filter out most of the interference energy and achieve an inhibitory effect. However, the suppression performance of such spatial anti-interference methods depends on the null level of the array pattern design. When the difference between the interference power and the communication signal power exceeds the null filtering ability, the useful information still cannot be correctly decoded. Therefore, how to design an antenna array anti-interference method with suppression performance dynamically changing with the interference intensity, so as to be able to correctly decode useful information in different intensity interference environments is a key issue in spatial anti-interference technology. Summary of the Invention

[0003] The present invention is to solve the problem that the suppression ability of the existing spatial anti-interference system is fixed and the normal demodulation of communication signals cannot be guaranteed in a strong interference environment, and thus proposes an antenna array interference suppression method based on pattern reconstruction and cancellation.

[0004] The technical solution adopted by the present invention is as follows:

[0005] An antenna array interference suppression method based on pattern reconstruction and cancellation, which includes the following steps:

[0006] Step 1: The receiving end uses N antennas to receive N-channel analog signals from the wireless channel, and processes the N-channel analog signals through a preprocessing component respectively to obtain the data to be processed input to the array; N is a positive integer;

[0007] Step 2: The receiving end sums up the antenna components of the data to be processed input to the array obtained in Step 1 to obtain the data after processing the original pattern of the antenna array;

[0008] Step 3: Send the data after processing the original pattern obtained in Step 2 into a buffer;

[0009] Step 4: The receiving end calculates the arrival angle θ of the communication signal using the data to be processed input to the array obtained in Step 1 c and the arrival angle θ of the interference signalI ;

[0010] Step Five: The receiving end calculates the gain G of the original radiation pattern of the antenna array at the direction of θ c and the gain G at the direction of θ m1 ; I ; z1 ;

[0011] Step Six: The receiving end designs an ideal reconstructed radiation pattern, and combines the influence of the phases of the antenna components of the array input data to be processed in Step One on the characteristics of the reconstructed radiation pattern, and calculates the radiation pattern reconstruction factors w 1 , w 2 , …, w N , where the moduli of w 1 , w 2 , …, w N are all 1;

[0012] The ideal reconstructed radiation pattern is specifically:

[0013] One of the side lobes of the radiation pattern is aligned with the interference arrival angle described in Step Five, and the null is oriented towards the communication signal arrival angle described in Step Five. Denote the gain of the aforementioned side lobe as G s2 , and the null gain as G z2 . Maximize the difference between G s2 and G zmax on the premise of ensuring that the calculation bit width does not overflow, where: G zmax = max(G z1 , G z2 );

[0014] Step Seven: Multiply each antenna component of the array input data to be processed in Step One by the corresponding radiation pattern reconstruction factor in Step Six and sum them to obtain the data after processing by the reconstructed radiation pattern of the antenna array;

[0015] Step Eight: Calculate the scaling ratio G of the data after processing by the reconstructed radiation pattern f , where G f (dB) = G z1 (dB) – G s2 (dB);

[0016] Step Nine: Perform power attenuation with a gain of G f on the data after processing by the reconstructed radiation pattern in Step Seven to obtain the attenuated data;

[0017] Step Ten: Read the data after processing by the original radiation pattern from the buffer described in Step Three, subtract the attenuated data described in Step Nine to obtain the interference-canceled data, and output it to the subsequent receiving and detection module to complete one-time interference suppression of the antenna array based on radiation pattern reconstruction cancellation.

[0018] The beneficial effects obtained by the invention are as follows: The present invention proposes an antenna array interference suppression method based on pattern reconstruction cancellation. Without additional increasing the hardware resources used by the antenna array, it makes full use of the computing resources of the processor. On the basis of the original receiver, it additionally adjusts the phases of the received data of each antenna component to complete pattern reconstruction, and cancels the processed data after pattern reconstruction with the original processed data to form a secondary superposition of signals, thereby enhancing the interference suppression ability. The interference suppression effect of the present invention is positively correlated with the interference intensity, ensuring that the signal-to-interference-plus-noise ratio after interference suppression is a fixed value, and still being able to ensure the normal demodulation of communication signals under strong interference, which is helpful for space-division interference suppression and improving the spatial multiplexing ability. Description of the Drawings

[0019] Figure 1 is a schematic diagram of the signal flow of an antenna array interference suppression method based on pattern reconstruction cancellation according to the present invention;

[0020] Figure 2 is a schematic diagram of the original pattern model of the antenna array of an antenna array interference suppression method based on pattern reconstruction cancellation according to the present invention;

[0021] Figure 3 is a schematic diagram of the reconstructed pattern model of an antenna array interference suppression method based on pattern reconstruction cancellation according to the present invention. Detailed Embodiments

[0022] Detailed Embodiment 1: In combination with Figures 1 - 3 this embodiment is described. An antenna array interference suppression method based on pattern reconstruction cancellation includes the following steps:

[0023] Step 1: The receiving end uses N antennas to receive N channels of analog signals from the wireless channel, and respectively processes the N channels of analog signals through a preprocessing component to obtain the data to be processed input to the array; N is a positive integer;

[0024] Among them, the preprocessing component specifically includes:

[0025] a low-noise amplifier, a downconverter, an analog-to-digital converter, and a filter;

[0026] Step 2: Sum the antenna components of the data to be processed input to the array in Step 1 to obtain the data after processing the original pattern of the antenna array;

[0027] Step 3: Send the data after processing the original pattern obtained in Step 2 into a buffer;

[0028] Step 4: The receiving end calculates the arrival angle θ c of the communication signal and the arrival angle θ I of the interference signal by using the data to be processed input to the array obtained in Step 1;

[0029] The specific calculation method for the arrival angles of the communication signal and the interference signal is as follows:

[0030] Calculate the covariance matrix of the data to be processed at the input of the array in Step 1, obtain the array direction matrix from the arrangement of the antenna array, and use the MUSIC or ESPRIT algorithm to obtain the estimated arrival angle value;

[0031] Step 5, as Figure 2 shown, the receiving end calculates the gain G c of the original antenna array pattern in the direction of θ m1 and the gain G I in the direction of θ z1 ; Denote the communication signal as x c (n), with power P x , the interference signal as y I (n), with power P y , and the noise introduced by the analog device as z 1 (n), with power σ z1 ; Then the data after processing the original pattern in Step 2 is expressed as:

[0032]

[0033] The signal-to-interference-plus-noise ratio after processing the original pattern is:

[0034]

[0035] Step 6, the receiving end designs an ideal reconstructed pattern as Figure 3 shown, and combines the influence of the phases of the antenna components of the data to be processed at the input of the array in Step 1 on the characteristics of the reconstructed pattern to calculate the pattern reconstruction factors w 1 , w 2 , …, w N , where the modulus values of w 1 , w 2 , …, w N are all 1;

[0036] The specific ideal reconstructed pattern is:

[0037] One of the side lobes of the pattern is aligned with the interference arrival angle in Step 5, and the null is directed towards the communication signal arrival angle in Step 5. Let the aforementioned side lobe gain be G s2 , and the null gain be G z2 . Maximize the difference between G s2 and G zmax on the premise of ensuring that the calculation bit width does not overflow, where G zmax = max(G z1 , G z2 );

[0038] Step 7: Multiply each antenna component of the data to be processed input in Step 1 by the corresponding pattern reconstruction factor in Step 6 and sum them to obtain the processed data of the reconstructed pattern of the antenna array, expressed as:

[0039]

[0040] where z 2 (n) is the noise introduced during the simulation device and the calculation process of the reconstructed pattern, and the power is σ z2 .

[0041] Step 8: Calculate the scaling ratio G f of the processed data of the reconstructed pattern, where G f (dB) = G z1 (dB) –

[0042] G s2 (dB);

[0043] Step 9: Perform power attenuation with a gain of G f on the processed data of the reconstructed pattern in Step 7 to obtain the attenuated data, expressed as:

[0044]

[0045] Step 10: Read the processed data of the original pattern from the buffer in Step 3, subtract the attenuated data in Step 9 to obtain the interference-cancelled data, and output it to the subsequent receiving and detecting module to complete the interference suppression of the antenna array based on pattern reconstruction cancellation. The interference-cancelled data is expressed as:

[0046]

[0047] The signal-to-interference-plus-noise ratio of the data output to the subsequent receiving and detecting module is:

[0048]

[0049] Under the reconstructed pattern characteristics in Step 6, compared with only the original branch processing in Step 2, the improvement ratio of the signal-to-interference-plus-noise ratio is:

[0050]

[0051] The beneficial effects obtained by the present invention are as follows: The present invention proposes an antenna array interference suppression method based on pattern reconstruction and cancellation. Without additionally increasing the hardware resources used by the antenna array, it makes full use of the computing resources of the processor. On the basis of the original receiver, it additionally adjusts the phases of the received data of each antenna component to complete pattern reconstruction, cancels the processed data after pattern reconstruction and the original processed data, forms a secondary superposition between signals, and improves the interference suppression ability. The interference suppression effect of the present invention is positively correlated with the interference intensity, ensuring that the signal-to-interference-plus-noise ratio after interference suppression is a fixed value, and still being able to ensure the normal demodulation of communication signals under strong interference, which helps in spatial interference suppression and improving the spatial multiplexing ability.

Claims

1. An antenna array interference suppression method based on pattern reconstruction and cancellation, characterized in that: It includes the following steps: Step 1: The receiving end receives N analog signals from a wireless channel using N antennas, and processes the N analog signals through preprocessing components respectively to obtain array input data to be processed; N is a positive integer; Step 2: The receiving end sums the antenna components of the array input data to be processed obtained in step 1 to obtain processed data of the original antenna array pattern; Step 3, sending the processed data of the original directional pattern obtained in step 2 into a buffer; Step 4: The receiving end uses the array input data to be processed obtained in step 1 to calculate the arrival angle θ of the communication signal c and the arrival angle θ of the interference signal I ; Step 5: The receiving end calculates the original radiation pattern of the antenna array at θ c Directional gain G m1 and in the direction θ I Gain G z1 ; Step 6: The receiving end designs an ideal reconstructed pattern, and calculates the pattern reconstruction factors w1, w2, ..., w based on the influence of the phase of each antenna component of the array input data to be processed in step 1 on the characteristics of the reconstructed pattern. N , where w1, w2, …, w N The modulus value of is 1; The ideal reconstruction direction diagram is specifically: One of the side lobes of the directional pattern is aligned with the interference arrival angle described in step 5, and the null is directed toward the communication signal arrival angle described in step 5. The side lobe gain is expressed as G s2 , the null gain is represented by G z2 , maximize G while ensuring that the calculation bit width does not overflow s2 With G zmax The difference, where: G zmax =max(G z1 ,G z2 ); Step 7: multiply each antenna component of the array input data to be processed in step 1 by the pattern reconstruction factor in step 6 and sum them up to obtain the processed data of the antenna array reconstructed pattern; Step 8: Calculate the scaling ratio G of the reconstructed directional pattern data after processing f , where G f (dB) = G z1 (dB)–G s2 (dB); Step 9: Gain the data after processing the reconstructed directional pattern in step 7 by G f The power is attenuated to obtain the attenuated data; Step 10: read the original pattern processed data from the buffer in step 3, subtract it from the attenuated data in step 9 to obtain the interference eliminated data, and output it to the subsequent receiving detection module to complete an antenna array interference suppression based on pattern reconstruction and cancellation.

2. The antenna array interference suppression method based on pattern reconstruction and cancellation according to claim 1 is characterized in that In step 1, the pre-processing component specifically includes: Low noise amplifiers LNA, downconverters, analog-to-digital converters and filters; The signal input end of the low noise amplifier LNA is the signal input end of the pre-processing component, and the signal output end of the low noise amplifier LNA is connected to the signal input end of the down converter; the signal output end of the down converter is connected to the signal input end of the analog-to-digital converter; the signal output end of the analog-to-digital converter is connected to the signal input end of the filter, and the signal output end of the filter is the signal output end of the pre-processing component.

3. The antenna array interference suppression method based on pattern reconstruction and cancellation according to claim 1 is characterized in that The processed data of the original antenna array pattern obtained in step 2 is expressed as: Where: x c (n) is: communication signal; y I (n) is the interference signal; z1(n) is the noise introduced by the analog device.

4. The antenna array interference suppression method based on pattern reconstruction and cancellation according to claim 3 is characterized in that In step 2, the signal-to-interference-noise ratio of the original directional pattern after processing is: Where: P x is: the power of the communication signal; P y is: the power of the interference signal; σ z1 is: noise z1(n) power.

5. The antenna array interference suppression method based on pattern reconstruction and cancellation according to claim 4 is characterized in that In step 4, the arrival angle θ of the communication signal is calculated based on the array input data to be processed obtained in step 1. c and the arrival angle θ of the interference signal I The specific method is: First, the covariance matrix of the array input data to be processed in step 1 is calculated, and the array direction matrix is ​​obtained according to the antenna array placement method. Then, the MUSIC or ESPRIT algorithm is used to obtain the estimated values ​​of the arrival angle of the communication signal and the arrival angle of the interference signal.

6. The antenna array interference suppression method based on pattern reconstruction and cancellation according to claim 5 is characterized in that In step 7, the antenna array reconstructs the pattern processed data, which is expressed as: Where: z2(n) is the noise introduced during the simulation of the device and the calculation of the reconstructed directional pattern.

7. The antenna array interference suppression method based on pattern reconstruction and cancellation according to claim 6 is characterized in that In step nine, the attenuated data is obtained as follows:

8. The antenna array interference suppression method based on pattern reconstruction and cancellation according to claim 7 is characterized in that In step 10, the obtained interference-eliminated data is expressed as:

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