CN113507307A - Space-time joint anti-interference method, device and equipment suitable for satellite communication - Google Patents

Abstract

The invention discloses a space-time joint anti-jamming method, device and equipment suitable for satellite communication. The method comprises: using a MUSIC algorithm to estimate the direction of arrival of a received signal; using a linear constraint minimum variance optimization criterion to solve a beamforming weight vector; Perform the first-level interference suppression processing on the received signal according to the beamforming weight vector; expand the dimension of the signal after the first-level interference suppression processing; use the space-time processing method based on the maximum signal interference-to-noise ratio criterion to solve the beamforming again Weight vector; perform the second-level interference suppression processing on the dimensionally expanded signal according to the beamforming weight vector obtained by re-solving; use the standard MLSE method to detect the signal after the second-level interference suppression processing, and recover useful symbols sequence. The invention adopts a two-level interference suppression method to improve the reliability of the Beidou satellite navigation system providing wireless communication services to power grid equipment in the interference scenario.

Description

A space-time joint anti-jamming method, device and equipment suitable for satellite communication

technical field

The present invention relates to the technical field of antenna array signal processing, in particular to a space-time joint anti-jamming method, device and device suitable for satellite communication.

Background technique

At present, the Beidou satellite navigation system has fully realized all-weather services such as accurate navigation, timing, positioning and short message communication for China, playing an increasingly important role in my country's economic and social development. Because satellite communication has obvious advantages and is less restricted by objective factors such as geographical location and time, it has developed rapidly, but it still faces certain problems in the process of development, and one of the challenges is the increasingly complex electromagnetic environment. Due to the large amount of electromagnetic interference in space (especially terrestrial space), even malicious interference, the satellite signal is extremely vulnerable. On the other hand, in power grid application scenarios, a large number of power equipment are usually arranged in remote areas, and functions such as the unification of power grid time benchmarks, power station environment monitoring, and electric vehicle monitoring are mainly achieved through the timing and positioning services provided by the Beidou satellite navigation system. When the interference is serious, the quality of the received signal of the ground navigation receiver will be degraded, which will seriously affect the service quality of the Beidou satellite navigation system, which may lead to irreparable power application losses. Therefore, how to suppress interference, improve the reliability and security of Beidou satellite navigation system communication, and ensure the service quality of Beidou satellite navigation system is of great significance.

SUMMARY OF THE INVENTION

In order to solve the problem of insufficient interference suppression capability in satellite communication, the present invention provides a space-time joint anti-jamming method suitable for satellite communication. The invention adopts a two-level interference suppression method to improve the reliability of the Beidou satellite navigation system providing wireless communication services to power grid equipment in the interference scenario.

The present invention is achieved through the following technical solutions:

A space-time joint anti-jamming method suitable for satellite communication, comprising:

Using multiple signal classification algorithm to estimate the direction of arrival of the received signal;

Based on the direction of arrival of the desired signal, a linear constrained minimum variance optimization criterion is used to solve the beamforming weight vector; the direction of arrival of the desired signal is the direction of arrival of the useful signal in the received signal;

Perform first-level interference suppression processing on the received signal according to the beamforming weight vector;

According to the principle of steering vector, the dimension of the signal after the first-level interference suppression processing is expanded;

The beamforming weight vector is solved again by using the space-time processing method based on the criterion of maximizing the signal interference-to-noise ratio;

Perform the second-level interference suppression processing on the dimensionally expanded signal according to the beamforming weight vector obtained by re-solving;

The standard maximum likelihood sequence estimation method is used to detect the signal after the second-level interference suppression processing, and the useful symbol sequence is recovered.

Preferably, the beamforming weight vector obtained by using the linear constrained minimum variance optimization criterion in the present invention is:

为约束矩阵，其由所得信号波达方向对应的导向矢量构造；

为与期望信号方向有关的约束向量；

为天线阵列接收信号的采样协方差矩阵。in,

is the constraint matrix, which is constructed by the steering vector corresponding to the direction of arrival of the obtained signal;

is the constraint vector related to the desired signal direction;

is the sampling covariance matrix of the received signal for the antenna array.

Preferably, the steps of performing the first-level interference suppression processing on the received signal according to the beamforming weight vector of the present invention are as follows:

对第

时刻天线阵列接收信号

加权处理，输出信号为

。Use the weight vector obtained by the solution

right

Time the antenna array receives the signal

Weighted processing, the output signal is

.

Preferably, the step of performing dimension expansion on the signal after the first-level interference suppression processing according to the steering vector principle is specifically as follows:

对

进行扩展，扩展维度为M，扩展后的信号为

。Corresponding steering vector according to the normal direction of the antenna array

right

Expand, the expanded dimension is M , and the expanded signal is

.

Preferably, the step of using the space-time processing method based on the maximum signal interference-to-noise ratio criterion of the present invention to solve the beamforming weight vector again specifically includes:

次快拍后接收到序列

，计算协方差矩阵

；go through

Sequence received after snapshot

, compute the covariance matrix

;

，进一步构造矩阵

；In the same way, the matrices are calculated separately in combination with the training sequence T known at the receiving end

, and further construct the matrix

;

最小特征值对应的特征向量

，则信道矢量估计为

；solve

The eigenvector corresponding to the smallest eigenvalue

, then the channel vector is estimated as

;

。Solve for the beamforming weight vector again

.

Preferably, the steps of performing the second-level interference suppression processing on the signal after dimension expansion according to the beamforming weight vector obtained by re-solving in the present invention are as follows:

对扩展维度后的信号

加权处理得到

实现第二级干扰抑制。According to the weight vector obtained by solving again

for the expanded dimension signal

weighted to get

A second level of interference suppression is achieved.

In a second aspect, the present invention provides a space-time joint anti-jamming device suitable for satellite communication, including a direction of arrival estimation module, a first-level interference suppression module, a second-level interference suppression module, and a sequence detection module;

The direction of arrival estimation module uses a multiple signal classification algorithm to estimate the direction of arrival of the received signal;

The first-level interference suppression module uses the linear constraint minimum variance optimization criterion to solve the beamforming weight vector, and performs weighting processing on the received signal to achieve the first-level interference suppression;

The second-level interference suppression module firstly expands the dimension of the signal after the first-level interference suppression according to the steering vector principle, and then uses the space-time processing method based on the criterion of maximizing the signal interference-to-noise ratio to solve the beamforming weight vector again. The second-level interference suppression is realized by weighting the signal after dimension expansion;

The sequence detection module adopts the standard maximum likelihood sequence estimation method to detect the signal after the second-level interference suppression, and recovers the useful symbol sequence.

In a third aspect, the present invention provides a satellite communication device, including the space-time joint anti-jamming device suitable for satellite communication according to the present invention.

The present invention has the following advantages and beneficial effects:

Compared with the existing airspace processing method and the JST method, the present invention has better anti-interference ability, and has obvious performance gain in the interference harsh environment. Therefore, the present invention is beneficial to improve the reliability of the Beidou satellite navigation system in providing the national grid equipment with communication services such as positioning and timing in a harsh environment of interference.

Description of drawings

The accompanying drawings described herein are used to provide further understanding of the embodiments of the present invention, and constitute a part of the present application, and do not constitute limitations to the embodiments of the present invention. In the attached image:

FIG. 1 is a schematic flowchart of the anti-interference method of the present invention.

FIG. 2 is a schematic diagram of the device structure of the present invention.

FIG. 3 is a schematic block diagram of the anti-jamming device of the present invention.

Figure 4 shows that when the training sequence length is 26, the information sequence length is 114, the number of antenna elements M=16, the number of multipaths is 3, the channel memory length is 4, the number of interfering users is 2, and the modulation method is BPSK. The comparison curve of the bit error rate (BER) between the method of the present invention and the JST method is used for the signal-to-interference ratio. The abscissa in the figure is the signal-to-interference ratio (unit: dB), and the ordinate is the bit error rate (BER). The mark "○" in the figure represents the JST method, and "□" represents the method of the present invention.

Figure 5 shows that when the training sequence length is 26, the information sequence length is 114, the number of antenna elements M=16, the number of multipaths is 3, the channel memory length is 4, the number of interfering users is 2, and the modulation method is BPSK. When the signal-to-interference ratio is used, the comparison curve of the bit error rate (BER) of the method of the present invention and the anti-interference method based on the LCMV optimization criterion is adopted. The abscissa in the figure is the signal-to-interference ratio (unit: dB), and the ordinate is the bit error rate (BER). The mark "○" in the figure represents the anti-interference method based on the LCMV optimization criterion, and "□" represents the method of the present invention.

Fig. 6 shows that when the training sequence length is 26, the information sequence length is 114, the number of antenna elements M=16, the number of multipaths is 3, the channel memory length is 4, the number of interfering users is 2, and the modulation method is BPSK, the present invention is adopted. Comparison curves of the bit error rate (BER) of the method at different signal-to-noise ratios. The abscissa in the figure is the signal-to-interference ratio (unit: dB), and the ordinate is the bit error rate (BER). The mark "○" in the figure represents the anti-interference method based on the LCMV optimization criterion, and "□" represents the method of the present invention.

Fig. 7 shows that when the training sequence length is 26, the information sequence length is 114, the number of antenna elements M=16, the number of multipaths is 3, the channel memory length is 4, the number of interfering users is 2, and the modulation method is BPSK, the present invention is adopted. Comparison curves of the bit error rate (BER) of the method at different signal-to-noise ratios. The abscissa in the figure is the signal-to-noise ratio (unit: dB), and the ordinate is the bit error rate (BER). The mark "×" in the figure represents the bit error rate curve of the method of the present invention when the signal-to-interference ratio is -40dB, "○" represents the bit error rate curve of the method of the present invention when the signal-to-interference ratio is -30dB, and "◇" represents the signal-to-interference ratio The bit error rate curve of the method of the present invention when the ratio is -20dB, "□" represents the bit error rate curve of the method of the present invention when the signal-to-interference ratio is 0dB.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and the accompanying drawings. as a limitation of the present invention.

Example 1

At present, anti-jamming technologies mainly include the following types of technologies:

Time-domain anti-interference technology: Its core idea is to use digital signal processing technology to design an adaptive filter to process the received signal in the time domain to suppress interference. Time-domain filtering technology has a strong inhibitory effect on narrow-band interference. For example, the time-domain anti-jamming chip developed by Mayflower Company in the United States still has a good inhibitory effect on narrow-band interference with interference power greater than 30dB.

Frequency domain anti-interference technology: This technology mainly uses Fast Fourier Transform (FFT, Fast Fourier Transform) to transform the signal from the time domain to the frequency domain, and further suppresses the power spectrum of the interference component in the frequency domain to achieve the purpose of anti-interference. The frequency-domain anti-jamming technology is easy to implement, and can provide a lower null depth than the time-domain anti-jamming technology, but the frequency-domain anti-jamming technology will weaken the satellite signal while suppressing the interference.

Spatial anti-jamming technology: This technology uses reasonable optimization criteria to adaptively solve the beamforming weight vector according to the difference in the direction of arrival of the desired signal and the interference signal in space. The direction of the desired signal is aligned, and the null position is aligned with the direction of the interference signal, thereby suppressing interference. Airspace anti-jamming technology has been widely concerned by researchers because of its excellent anti-jamming performance.

Space-time joint anti-jamming technology: This method combines time-domain processing technology on the basis of air-space anti-jamming technology, overcomes the shortcomings of pure air-space anti-jamming technology that the interference suppression capability is limited by the number of array elements, and greatly improves the antenna array. The freedom of interference suppression and the introduction of time domain processing technology further improve the anti-interference performance. This technology is one of the hotspots in satellite communication anti-jamming research.

In practical applications, the power of the interfering signal is usually relatively large, and the currently used power inversion method has no gain for the satellite signal, and even weakens the satellite signal. Therefore, considering the excellent performance of the airspace anti-jamming method and the joint space-time (JST, Joint Space-Time) anti-jamming method, this embodiment proposes a joint space-time anti-jamming method suitable for satellite communication. The method firstly uses the Multiple Signal Classification algorithm (MUSIC, Multiple SignalClassification) to estimate the direction of arrival (DOA, Direction of Arrival) of the signal, and then uses the Linear Constraint Minimum Variance (LCMV, Linear Constraint Minimum Variance) optimization criterion to solve the beam according to the desired signal direction. The weight vector is shaped, and the received signal is weighted to achieve the first-level interference suppression. Then, the space-time processing method based on the maximum Signal to Interference and Noise Ratio (SINR, Signal to Interference and Noise Ratio) criterion is used to solve the channel vector and beam assignment. Then, the signal after the first-level interference suppression is weighted again to achieve the second-level interference suppression. Finally, the standard maximum likelihood sequence estimation (MLSE, Maximum Likelihood Sequence Estimation) is used for the received signal sequence after the two-level interference suppression. Estimation) method to receive. Compared with the anti-interference method based on LCMV optimization criterion, JST method, Least Mean Square (LMS, Least Mean Square) method, Recursive Least Square (RLS, Recursive Least Square) method, Constant Modulus Algorithm (CMA, Constant Modulus Algorithm) ), the method proposed in this embodiment has better interference suppression capability and beamforming gain.

Specifically, as shown in FIG. 1 , the method of this embodiment includes:

Step 101, estimating the direction of arrival of the received signal.

Step 101 of this embodiment adopts the MUSIC algorithm to estimate the direction of arrival of the signal, that is, perform eigendecomposition on the sampling covariance matrix R of the signal received by the antenna array, construct the signal subspace and the noise subspace according to the obtained eigenvectors, and further obtain the array space spectral function, and finally estimate the direction of arrival of the signal through the spectral peak search algorithm.

Step 102 , based on the direction of arrival of the desired signal, using the linear constrained minimum variance optimization criterion (LCMV optimization criterion) to solve the beamforming weight vector. The direction of arrival of the desired signal is the direction of arrival of the useful signal in the actual received signal.

The beamforming weight vector solved in this embodiment is:

由步骤101所得信号波达方向对应的导向矢量构造，

是与期望信号方向有关的约束向量。where the constraint matrix

Constructed by the steering vector corresponding to the direction of arrival of the signal obtained in step 101,

is the constraint vector related to the desired signal direction.

Step 103: Perform first-level interference suppression processing on the received signal according to the beamforming weight vector.

对第

时刻天线阵列接收信号

加权处理，输出信号为

。Step 103 in this embodiment specifically includes: the weight vector obtained by solving in step 102

right

Time the antenna array receives the signal

Weighted processing, the output signal is

.

Step 104, according to the steering vector principle, perform dimension expansion on the signal after the first-level interference suppression.

对

进行扩展，扩展维度为M，扩展后的信号为

，其中M为阵元数。Step 104 in this embodiment corresponds to the steering vector according to the normal direction of the antenna array

right

Expand, the expanded dimension is M , and the expanded signal is

, where M is the number of array elements.

Step 105 , using the space-time processing method (JST algorithm) based on the criterion of maximizing the signal-to-interference-to-noise ratio (SINR criterion) to solve the beamforming weight vector again.

Step 105 of this embodiment specifically includes:

次快拍后接收到序列

，计算协方差矩阵

；Step 201, after

Sequence received after snapshot

, compute the covariance matrix

;

，进一步构造矩阵

；In the same way, the matrices are calculated separately in combination with the training sequence T known at the receiving end

, and further construct the matrix

;

最小特征值对应的特征向量

，则信道矢量估计为

；Step 202, solve

The eigenvector corresponding to the smallest eigenvalue

, then the channel vector is estimated as

;

。Step 203, solve the beamforming weight vector again

.

Step 106 , perform a second-level interference suppression process on the signal after the expanded dimension according to the weight vector obtained by re-solving.

对扩展维度后的信号

加权处理得到

实现第二级干扰抑制。Step 106 of this embodiment is based on the weight vector obtained by re-solving

for the expanded dimension signal

weighted to get

A second level of interference suppression is achieved.

Step 107 , using the standard MLSE method to detect the signal after the second-level interference suppression processing, and recover the useful symbol sequence.

对经过第二级干扰抑制后的信号

进行检测，恢复出有用序号序列。Step 107 in this embodiment is based on the obtained channel vector

For the signal after the second level of interference suppression

Carry out detection and recover the useful serial number sequence.

，根据所得

对天线阵列接收信号

进行加权处理实现第一级干扰抑制，经过第一级抑制后干扰信号能量已经充分降低。接着根据导向矢量原理对经过第一级干扰抑制后的信号

扩展维度，再采用基于最大化信干噪比准则的空时处理方法求解信道矢量

和波束赋形权重矢量

，根据所得

对扩展维度后的信号

进行加权处理实现第二级干扰抑制，最后根据所得信道矢量

对经过两级干扰抑制后的信号序列采用标准MLSE方法进行检测，进一步提升算法抗干扰性能。The method proposed in this embodiment adopts a two-stage interference suppression architecture to achieve the purpose of anti-interference. First estimate the direction of arrival of the signal, and then use the LCMV optimization criterion to solve the beamforming weight vector based on the desired signal direction

, according to the income

Receive signal to antenna array

The weighting process is performed to achieve the first-level interference suppression. After the first-level suppression, the energy of the interference signal has been sufficiently reduced. Then, according to the principle of steering vector, the signal after the first-level interference suppression is

Expand the dimension, and then use the space-time processing method based on the criterion of maximizing the signal-to-interference-to-noise ratio to solve the channel vector

and the beamforming weight vector

, according to the income

for the expanded dimension signal

Perform weighting processing to achieve the second-level interference suppression, and finally according to the obtained channel vector

The standard MLSE method is used to detect the signal sequence after two-level interference suppression, which further improves the anti-interference performance of the algorithm.

This embodiment also proposes a computer device (receiver device) for executing the above method of this embodiment.

Specifically, as shown in FIG. 2, a computer device includes a processor, an internal memory and a system bus; various device components including the internal memory and the processor are connected to the system bus. A processor is a piece of hardware used to execute computer program instructions through the basic arithmetic and logical operations in a computer system. Internal memory is a physical device used to temporarily or permanently store computing programs or data (eg, program state information). The system bus can be any of the following types of bus structures, including a memory bus or memory controller, a peripheral bus, and a local bus. The processor and the internal memory can communicate data through the system bus. The internal memory includes read-only memory (ROM) or flash memory (not shown in the figure), and random access memory (RAM). RAM usually refers to the main memory loaded with the operating system and computer programs.

Computer equipment typically includes an external storage device. The external storage device can be selected from a variety of computer-readable media, which refers to any available media that can be accessed by a computer device, including both removable and fixed media. For example, computer readable media include, but are not limited to, flash memory (micro SD card), CD-ROM, digital versatile disc (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or available Any other medium that stores the required information and can be accessed by a computer device.

Computer equipment may be logically connected to one or more network terminals in a network environment. The network terminals can be personal computers, servers, routers, smart phones, tablet computers, or other public network nodes. The computer equipment is connected to the network terminal through a network interface (local area network LAN interface). A local area network (LAN) refers to a computer network that is interconnected in a limited area, such as a home, school, computer laboratory, or office building using network media. WiFi and twisted pair cabling Ethernet are two of the most commonly used technologies for building local area networks.

It should be noted that other computer systems that include more or fewer subsystems than computer devices are also suitable for use in the invention.

As described in detail above, the computer device suitable for this embodiment can perform the specified operations of the joint space-time anti-jamming method. The computer device performs these operations through a processor in the form of software instructions executed in a computer-readable medium. These software instructions may be read into memory from a storage device or from another device through a local area network interface. The software instructions stored in the memory cause the processor to perform the above-described method of processing group member information. In addition, the present invention can also be implemented by hardware circuits or hardware circuits combined with software instructions. Therefore, implementing this embodiment is not limited to any specific combination of hardware circuitry and software.

Example 2

This embodiment proposes a space-time joint anti-jamming device suitable for satellite communication. Specifically, as shown in FIG. 3 , the device in this embodiment includes a direction of arrival estimation module, a first-level interference suppression module, a second-level interference suppression module, Sequence detection module.

Among them, the direction estimation module uses the MUSIC algorithm to estimate the direction of arrival of the received signal.

The first-level interference suppression module uses the LCMV optimization criterion to solve the beamforming weight vector, and weights the received signal to achieve the first-level interference suppression.

The second-level interference suppression module firstly expands the dimension of the signal after the first-level interference suppression according to the principle of steering vector, and then uses the space-time processing method based on the SINR criterion (that is, the JST algorithm) to solve the beamforming weight vector and the number of signals again. The second-level interference suppression is realized by performing weighting processing on the dimension-expanded signal.

The sequence detection module uses the standard MLSE method to detect the signal after the second-level interference suppression, and recovers the useful symbol sequence.

This embodiment also proposes a satellite communication device, which includes the above-mentioned anti-jamming device.

Example 3

This embodiment simulates and verifies the anti-interference method proposed in the above-mentioned embodiment. The specific conditions of the simulation experiment are: the length of the training sequence is 26, the length of the information sequence is 114, the number of antenna elements is M=16, the number of multipaths is 3, and the channel memory is The length is 4, the number of interfering users is 2, and the modulation method is BPSK.

FIG. 4 is a comparison curve of the bit error rate (BER) between the method of the present invention and the JST method under different signal-to-interference ratios under the above-mentioned specific simulation conditions. The abscissa in the figure is the signal-to-interference ratio (unit: dB), and the ordinate is the bit error rate (BER). The mark "○" in the figure represents the JST method, and "□" represents the method of the present invention.

时，相比JST算法，本发明方法的抗干扰性能提升了约15dB。It can be seen from FIG. 4 that the anti-interference performance of the method of the present invention is better than that of the JST method. When the code rate

When compared with the JST algorithm, the anti-interference performance of the method of the present invention is improved by about 15dB.

FIG. 5 is a comparison curve of the bit error rate (BER) of the method of the present invention and the anti-interference method based on the LCMV optimization criterion under the above specific simulation conditions at different signal-to-interference ratios. The abscissa in the figure is the signal-to-interference ratio (unit: dB), and the ordinate is the bit error rate (BER). The mark "○" in the figure represents the anti-interference method based on the LCMV optimization criterion, and "□" represents the method of the present invention.

时，相比基于LCMV优化准则抗干扰方法，本发明方法的抗干扰性能提升了约18dB。It can be seen from FIG. 5 that the anti-interference performance of the method of the present invention is better than that of the anti-interference method based on the LCMV optimization criterion. When the error rate is

When compared with the anti-jamming method based on the LCMV optimization criterion, the anti-jamming performance of the method of the present invention is improved by about 18dB.

FIG. 6 is a comparison curve of the bit error rate (BER) of the method of the present invention at different signal-to-noise ratios under the above-mentioned specific simulation conditions. The abscissa in the figure is the signal-to-noise ratio (unit: dB), and the ordinate is the bit error rate (BER). The mark "×" in the figure represents the bit error rate curve of the method of the present invention when the signal-to-interference ratio is -40dB, "○" represents the bit error rate curve of the method of the present invention when the signal-to-interference ratio is -30dB, and "◇" represents the signal-to-interference ratio The bit error rate curve of the method of the present invention when the ratio is -20dB, "□" represents the bit error rate curve of the method of the present invention when the signal-to-interference ratio is 0dB.

It can be seen from FIG. 6 that when the signal-to-interference ratio is -40dB and -30dB, the bit error rate curve of the method of the present invention has a flattening phenomenon, and the anti-interference performance of the algorithm is greatly affected by the interference power. As the signal-to-interference ratio increases, the anti-interference ability of the algorithm improves. When the signal-to-interference ratio is 0dB, the leveling phenomenon disappears, and the bit error rate decreases rapidly with the increase of the signal-to-noise ratio.

7 is a comparison curve of the bit error rate (BER) between the method of the present invention and the LMS method, the RLS method, the CMA method, the anti-jamming method based on the LCMV optimization criterion, and the JST method under the above-mentioned specific simulation conditions under different signal-to-interference ratios. The abscissa in the figure is the signal-to-interference ratio (unit: dB), and the ordinate is the bit error rate (BER). The mark “+” in the figure represents the BER curve of the LMS method, “×” represents the BER curve of the RLS method, “*” represents the BER curve of the CMA method, and “◇” represents the anti-interference based on the LCMV optimization criterion The bit error rate curve of the method, "○" represents the bit error rate curve of the JST method, and "□" represents the bit error rate curve of the method of the present invention.

时，相比于JST方法，本发明方法的抗干扰性能提升约15dB；相比于基于LCMV优化准则的抗干扰方法，本发明方法的抗干扰性能提升约18dB；相比于LMS方法、RLS方法及CMA方法，本发明方法的抗干扰性能具有更明显的性能提升。It can be seen from FIG. 7 that, compared with the traditional anti-interference method, the method of the present invention has better anti-interference performance. When the error rate is

When compared with the JST method, the anti-jamming performance of the method of the present invention is improved by about 15dB; compared with the anti-jamming method based on the LCMV optimization criterion, the anti-jamming performance of the method of the present invention is improved by about 18dB; compared with the LMS method and the RLS method And the CMA method, the anti-interference performance of the method of the present invention has more obvious performance improvement.

The specific embodiments described above further describe the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (8)

1. A space-time joint anti-interference method suitable for satellite communication is characterized by comprising the following steps:

estimating the direction of arrival of the received signal by adopting a multiple signal classification algorithm;

solving a beamforming weight vector by adopting a linear constraint minimum variance optimization criterion based on the direction of arrival of the expected signal; the direction of arrival of the expected signal is the direction of arrival of a useful signal in the received signal;

performing first-stage interference suppression processing on the received signals according to the beamforming weight vector;

performing dimensionality extension on the signal subjected to the first-stage interference suppression processing according to a guide vector principle;

solving the beamforming weight vector again by adopting a space-time processing method based on a maximized signal interference-to-noise ratio criterion;

performing second-stage interference suppression processing on the signals subjected to the dimensionality extension according to the beamforming weight vector obtained by solving again;

and detecting the signal subjected to the second-stage interference suppression by adopting a standard maximum likelihood sequence estimation method to recover the useful symbol sequence.

2. A space-time joint anti-interference method suitable for satellite communication according to claim 1, wherein the beamforming weight vector obtained by solving using a linear constraint minimum variance optimization criterion is:

wherein,

a constraint matrix constructed by steering vectors corresponding to the directions of arrival of the resulting signals;

is a constraint vector related to the desired signal direction;

a sampled covariance matrix of the signal is received for the antenna array.

3. A space-time joint anti-interference method suitable for satellite communication according to claim 2, wherein the step of performing the first-stage interference suppression processing on the received signal according to the beamforming weight vector specifically comprises:

using weight vectors obtained by solving

To the first

Time antenna array receiving signal

At the weightingOutputs a signal of

。

4. A space-time joint anti-interference method suitable for satellite communication according to claim 3, wherein the step of performing dimension expansion on the signal subjected to the first-stage interference suppression processing according to the steering vector principle specifically comprises:

corresponding guide vector according to normal direction of antenna array

To pair

Performing expansion, wherein the expanded dimension is a guide vector

Dimension (d) of

The signal after spreading is

。

5. A space-time joint anti-interference method suitable for satellite communication according to claim 4, wherein the step of solving the beamforming weight vector again by using a space-time processing method based on a maximized signal interference-to-noise ratio criterion specifically comprises:

through

Receiving sequence after sub-snapshot

Computing assistantVariance matrix

Similarly, the matrix is calculated respectively by combining the training sequence T known by the receiving end

Further constructing a matrix

；

Solving for

Feature vector corresponding to minimum feature value

Then the channel vector is estimated as

；

Re-solving beamforming weight vectors

。

6. A space-time joint anti-interference method suitable for satellite communication according to claim 5, wherein the step of performing the second-stage interference suppression processing on the signals subjected to the dimension expansion according to the beamforming weight vector obtained by the re-solving specifically comprises:

according to the beam forming weight vector obtained by solving again

For signals after dimension expansion

The weighting process is obtained

And realizing second-stage interference suppression.

7. A space-time joint anti-jamming device suitable for satellite communication is characterized by comprising a direction-of-arrival estimation module, a primary interference suppression module, a secondary interference suppression module and a sequence detection module;

the direction-of-arrival estimation module estimates the direction of arrival of the received signal by adopting a multi-signal classification algorithm;

the primary interference suppression module solves a beamforming weight vector by adopting a linear constraint minimum variance optimization criterion, and performs weighting processing on a received signal to realize primary interference suppression;

the secondary interference suppression module firstly performs dimensionality extension on the signals subjected to the primary interference suppression according to a guide vector principle, then solves a beam forming weight vector again by adopting a space-time processing method based on a maximized signal interference-to-noise ratio criterion, and performs weighting processing on the signals subjected to the dimensionality extension to realize secondary interference suppression;

and the sequence detection module detects the signal subjected to the second-stage interference suppression by adopting a standard maximum likelihood sequence estimation method, and recovers a useful symbol sequence.

8. A satellite communication device, characterized by comprising the space-time joint interference rejection apparatus suitable for satellite communication according to claim 7.

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