Multi-dimensional channel optimization and interference suppression method applied to satellite communication system

Abstract

The invention provides a multi-dimensional channel optimization and interference suppression method applied to a satellite communication system. The method comprises the following steps: S1, constructing a space-time heterogeneous array; s2, separating multiple paths of a channel based on a space-time heterogeneous array; s3, estimating the separated multi-path channel parameters; s4, improving the degree of freedom of the space-time heterogeneous array by using the fast reconfigurable capability of the metasurface antenna pattern; s5, optimally designing parameters of the metasurface antenna according to a channel estimation result; multi-path channel parameter information is mined from a received signal, so that the upper limit of key entropy is further improved, and the safety performance of wireless endogenous information is enhanced; and meanwhile, differences among multiple paths are utilized, so that the signal spatial resolution capability can be further improved, the interference suppression capability is improved, and the communication safety performance is enhanced.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a multi-dimensional channel optimization and interference suppression method applied to a satellite communication system. Background Art

[0002] Satellite communication is the communication between radio communication stations on the earth using satellites as relays. The satellite communication system consists of two parts: satellite and earth station. The characteristics of satellite communication are: large communication range, as long as it is within the range covered by the radio waves emitted by the satellite, communication can be carried out from any two points; it is not easily affected by land disasters; it can be opened as long as the earth station circuit is set up; it can be received at multiple locations at the same time, and can economically realize broadcast and multi-address communication; the circuit setting is very flexible, and the over-concentrated traffic can be dispersed at any time; the same channel can be used in different directions or different intervals.

[0003] With the development of satellite communication technology, security issues are emerging one after another. One type is security issues at the information level. Such issues already exist widely in wired networks. To address such issues, people use cryptographic security methods to encrypt transmitted information and design authentication protocols to ensure the privacy and credibility of transmitted information. However, compared with this, a more serious security threat comes from the signal level. The intrinsic function of the communication system is to reliably send information to the destination. When this intrinsic function is lost, security protection at the information level will be meaningless.

[0004] First, the signal is easy to be intercepted. No matter what encryption method is used for the signal content, it cannot prevent the signal itself from being intercepted. The intercepted signal is the basis for subsequent attack methods such as decryption and replay of the carried information. Second, the signal is easy to be interfered with. In many cases, it is only necessary to block the communication between the legitimate parties, and the attack purpose can be achieved without obtaining the information content.

[0005] Therefore, there is an urgent need for a multi-dimensional channel optimization and interference suppression method applied to satellite communication systems that can solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to provide a multi-dimensional channel optimization and interference suppression method applied to a satellite communication system to solve the problems existing in the above-mentioned prior art.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] The present invention provides a multi-dimensional channel optimization and interference suppression method applied to a satellite communication system, comprising the following steps:

[0009] S1. Construction of space-time heterogeneous array;

[0010] S2. Separate the multipath of the channel based on the space-time heterogeneous array;

[0011] S3. Estimate the separated multipath channel parameters;

[0012] S4. Improving the freedom of space-time heterogeneous arrays by using the fast reconfiguration capability of metasurface antenna patterns;

[0013] S5. Optimize and design the metasurface antenna parameters based on the channel estimation results.

[0014] Preferably, step S1 specifically includes:

[0015] S11. Construct a metasurface antenna receiving model;

[0016] S12. Constructing spatial heterogeneous array based on metasurface antenna receiving model;

[0017] S13. Constructing time-heterogeneous array based on metasurface antenna reception model;

[0018] S14. Unify the spatial heterogeneous array and the temporal heterogeneous array into a space-time heterogeneous array.

[0019] Preferably, the multi-stream signal receiving method of step S1 is: in spatial heterogeneity, the directional pattern of each antenna is adjusted to match the multipath so that they are superimposed in an optimal manner, and in temporal heterogeneity, the array design for different stream signals utilizes all degrees of freedom of the array and the antenna so that all antennas in the array achieve the best directional pattern for the multipath.

[0020] Preferably, step S2 specifically includes: changing the 1-bit coded metasurface antenna configuration parameters multiple times within a pilot symbol to form unrelated directional patterns, to achieve fast sampling of multipath channels, and to achieve multipath separation according to the sampling results.

[0021] Preferably, the estimation method of step S3 is:

[0022] During the duration of the kth pilot symbol, the metasurface antenna quickly changes the metamaterial unit state M times. Then, when the kth pilot symbol is sent, the received signal when the receiving end metasurface antenna adopts the Wth directional pattern is:

[0023] y km =v T A(θ)h BR (θ)s k +n km ;

[0024] in, is the pilot signal sent, is the sum of the received noise on each metamaterial unit, is the received noise on the i-th unit, and they are independent and identically distributed.

[0025] Arrange the M received signals into column vectors, that is:

[0026] y k =h BA s k +n k

[0027] =V T A(θ)h BR (θ)s k +n k ;

[0028] in, s k is a known signal;

[0029] Using the LS channel estimation algorithm, the channel estimation result is:

[0030]

[0031] in, Represents the pilot sequence.

[0032] Preferably, step S4 specifically includes: quickly switching the directional pattern of the metasurface antenna when receiving a signal, so that one receiving channel of the antenna is equivalent to multiple ones, and randomly switching the antenna directional pattern to suppress interference to prevent the information of the desired signal from being completely lost.

[0033] Preferably, step S5 specifically includes: using ICA to achieve blind channel estimation of desired signals and interference, performing space-time two-dimensional joint design of antenna parameters, and increasing the effective number of ADC bits by adding a minimum signal-to-interference ratio constraint at the antenna.

[0034] Compared with the prior art, the present invention has achieved the following beneficial technical effects:

[0035] The present invention provides a multi-dimensional channel optimization and interference suppression method for use in a satellite communication system, comprising the following steps: S1. constructing a space-time heterogeneous array; S2. separating the multipaths of a channel based on the space-time heterogeneous array; S3. estimating the separated multipath channel parameters; S4. improving the degree of freedom of the space-time heterogeneous array by utilizing the fast reconfiguration capability of a metasurface antenna pattern; S5. optimizing the design of metasurface antenna parameters according to the channel estimation result; by mining the multipath channel parameter information from a received signal, the upper limit of the key entropy is further increased, and the wireless intrinsic information security performance is enhanced; and by utilizing the differences between the multipaths, the spatial resolution capability of the signal can be further improved, thereby improving the interference suppression capability and enhancing the communication security performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0037] Figure 1 A flow chart of a multi-dimensional channel optimization and interference suppression method applied in a satellite communication system provided by the present invention. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] The purpose of the present invention is to provide a multi-dimensional channel optimization and interference suppression method applied to a satellite communication system to solve the problems existing in the prior art.

[0040] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] Embodiment 1:

[0042] This embodiment provides a multi-dimensional channel optimization and interference suppression method applied to a satellite communication system, comprising the following steps:

[0043] S1. Constructing a space-time heterogeneous array; specifically:

[0044] S11. Construct a metasurface antenna receiving model;

[0045] S12. Constructing spatial heterogeneous array based on metasurface antenna receiving model;

[0046] S13. Constructing time-heterogeneous array based on metasurface antenna reception model;

[0047] S14. Unify the spatial heterogeneous array and the temporal heterogeneous array into a spatial-temporal heterogeneous array;

[0048] The multi-stream signal receiving method using the above steps is as follows: in spatial heterogeneity, the directional pattern of each antenna is adjusted to match the multipath so that they are superimposed in the best way; in temporal heterogeneity, the array design for different stream signals utilizes all degrees of freedom of the array and the antenna so that all antennas in the array achieve the best directional pattern for the multipath;

[0049] S2. Separate the multipath of the channel based on the space-time heterogeneous array; change the 1-bit coded metasurface antenna configuration parameters multiple times within a pilot symbol to form unrelated directional patterns, realize fast sampling of the multipath channel, and separate the multipath according to the sampling results;

[0050] S3. Estimate the separated multipath channel parameters; estimation method:

[0051] During the duration of the kth pilot symbol, the metasurface antenna quickly changes the metamaterial unit state M times. Then, when the kth pilot symbol is sent, the received signal when the receiving end metasurface antenna adopts the Wth directional pattern is:

[0052] y km =v T A(θ)h BR (θ)s k +n km ;

[0053] in, is the pilot signal sent, is the sum of the received noise on each metamaterial unit, is the received noise on the i-th unit, and they are independent and identically distributed.

[0054]

[0055] Arrange the M received signals into column vectors, that is:

[0056] y k =h BA s k +n k

[0057] =V T A(θ)h B R(θ)s k +n k ;

[0058] in, s k is a known signal;

[0059] Using the LS channel estimation algorithm, the channel estimation result is:

[0060]

[0061] in, represents a pilot sequence;

[0062] S4. Use the fast reconfiguration capability of metasurface antenna patterns to improve the freedom of space-time heterogeneous arrays; quickly switch the pattern of the metasurface antenna when receiving signals, so that one receiving channel of the antenna is equivalent to multiple channels, and randomly switch the antenna pattern to suppress interference and prevent the complete loss of information of the desired signal;

[0063] S5. According to the channel estimation results, the metasurface antenna parameters are optimized and designed, and the blind channel estimation of the desired signal and interference is realized by using ICA. The antenna parameters are designed in two dimensions in space and time, and the effective number of ADC bits is increased by adding the minimum signal-to-interference ratio constraint at the antenna.

[0064] The method provided by the present invention mines multipath channel parameter information from the received signal, thereby further improving the upper limit of key entropy and enhancing the wireless intrinsic information security performance; at the same time, by utilizing the differences between multipaths, the spatial resolution capability of the signal can be further improved, thereby improving the interference suppression capability and enhancing the communication security performance.

[0065] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A multi-dimensional channel optimization and interference suppression method for satellite communication systems, characterized in that: The following steps are involved: S1. Construction of space-time heterogeneous array; S2. Separate the multipath of the channel based on the space-time heterogeneous array; S3. Estimate the separated multipath channel parameters; S4. Improving the freedom of space-time heterogeneous arrays by using the fast reconfiguration capability of metasurface antenna patterns; S5. Optimize and design the metasurface antenna parameters based on the channel estimation results.

2. The multi-dimensional channel optimization and interference suppression method for satellite communication system according to claim 1, characterized in that: Step S1 is specifically as follows: S11. Construct a metasurface antenna receiving model; S12. Constructing spatial heterogeneous array based on metasurface antenna receiving model; S13. Constructing time-heterogeneous array based on metasurface antenna reception model; S14. Unify the spatial heterogeneous array and the temporal heterogeneous array into a space-time heterogeneous array.

3. The multi-dimensional channel optimization and interference suppression method for satellite communication system according to claim 2, characterized in that: The multi-stream signal receiving method in step S1 is as follows: in spatial heterogeneity, the directional pattern of each antenna is adjusted to match the multipath so that they are superimposed in the best way; in temporal heterogeneity, the array design for different stream signals utilizes all degrees of freedom of the array and the antenna so that all antennas in the array achieve the best directional pattern for the multipath.

4. The multi-dimensional channel optimization and interference suppression method for satellite communication system according to claim 1, characterized in that: Step S2 specifically includes: changing the 1-bit coded metasurface antenna configuration parameters multiple times within a pilot symbol to form unrelated directional patterns, realizing fast sampling of multipath channels, and realizing multipath separation according to the sampling results.

5. The multi-dimensional channel optimization and interference suppression method for satellite communication system according to claim 1, characterized in that: Estimation method of step S3: During the duration of the kth pilot symbol, the metasurface antenna quickly changes the metamaterial unit state M times. Then, when the kth pilot symbol is sent, the received signal when the receiving end metasurface antenna adopts the Wth directional pattern is: y km =v T A(θ)h BR (i)s k +n km ; in, is the pilot signal sent, is the sum of the received noise on each metamaterial unit, is the received noise on the i-th unit, and they are independent and identically distributed. Arrange the M received signals into column vectors, that is: y k =h BA s k +n k =V T A(θ)h BR (i)s k +n k ; in, s k is a known signal; Using the LS channel estimation algorithm, the channel estimation result is: in, Represents the pilot sequence.

6. The multi-dimensional channel optimization and interference suppression method for satellite communication system according to claim 1, characterized in that: Step S4 is specifically as follows: when receiving a signal, the directional pattern of the metasurface antenna is quickly switched, so that one receiving channel of the antenna is equivalent to multiple receiving channels, and the antenna directional pattern is randomly switched to suppress interference and prevent the information of the desired signal from being completely lost.

7. The multi-dimensional channel optimization and interference suppression method for satellite communication system according to claim 1, characterized in that: Step S5 is specifically as follows: using ICA to achieve blind channel estimation of the desired signal and interference, performing space-time two-dimensional joint design of antenna parameters, and increasing the effective number of ADC bits by adding a minimum signal-to-interference ratio constraint at the antenna.

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