A spatial filtering method, system, device and medium for a satellite-borne navigation receiver

Abstract

The present invention relates to a spatial domain filtering method, system, device and medium of a satellite-borne navigation receiver, and the method comprises the following steps: obtaining the host satellite position and navigation satellite position of the current epoch; using the obtained host satellite position and navigation satellite position of the current epoch to estimate the arrival direction and power attenuation coefficient of the navigation signal; using the arrival direction and power attenuation coefficient of the navigation signal, calculating or looking up a table to obtain a beamforming weight coefficient; obtaining a combined signal according to the correlation between the beamforming weight coefficient and the received navigation signal, and outputting it for subsequent processing. The spatial domain filtering method adopted by the present invention calculates the Lagrange multiplier by an iterative method and then determines the beamforming weight coefficient. It can be seen from the simulation results that the spatial domain filtering method proposed by the present invention can effectively improve the signal-to-interference ratio. Therefore, the present invention can be widely used in the field of radio navigation technology.

Description

Technical Field

[0001] The present invention belongs to the field of radio navigation technology, and in particular relates to a spatial domain filtering method, system, device and medium for a medium- and high-orbit anti-interference satellite-borne navigation receiver. Background Art

[0002] A Global Navigation Satellite Systems (GNSS) receiver is a satellite-borne navigation receiver installed on a non-navigation satellite and is used to determine the orbit of the non-navigation satellite and provide timing for the satellite.

[0003] Medium- and high-orbit satellite-borne navigation receivers are satellite-borne navigation receivers installed on medium- and high-orbit satellites, and are an important source of time and space references for medium- and high-orbit satellites. When the orbital altitude of medium- and high-orbit satellites is almost the same as or higher than that of GNSS satellites, medium- and high-orbit satellite-borne navigation receivers can only be installed on the ground to receive the side lobe and part of the main lobe signals of GNSS satellites that are not blocked by the earth on one side of the earth. At this time, the navigation interference signal from the ground can also be received by the medium- and high-orbit satellite-borne navigation receiver, and the transmission path of the interference signal is significantly smaller than the normal GNSS navigation signal from the GNSS satellite. Under this condition, the navigation interference signal from the ground poses a major security threat to the Smart Skynet time and space reference system.

[0004] After years of development, people have invented many anti-interference methods for navigation receivers. At present, the anti-interference technologies for navigation receivers mainly include: time domain filtering technology, frequency domain filtering technology, time-frequency (TF) filtering technology, spatial filtering (SF) technology, spatial-temporal adaptive processing (STAP) technology, spatial-frequency adaptive processing (SFAP) technology, and even spatial-time-frequency filtering technology. Each filtering technology has its own pertinence and application conditions. Time domain filtering and frequency domain filtering have a good suppression effect on narrowband interference, but are almost ineffective against broadband interference; spatial domain filtering is a more general method that uses an antenna array with multiple array elements to weight the received signal, thereby generating a zero point in the antenna pattern facing the interference direction; for technologies such as STAP and SFAP, the application effect is good but the calculation amount is very large, and it is only applicable to ground receivers.

[0005] In a complex electromagnetic environment, a single anti-interference method can no longer meet the needs of satellite-borne navigation receivers, because no anti-interference technology can solve all interference problems faced by navigation receivers. Summary of the invention

[0006] In view of the above problems, the purpose of the present invention is to provide a spatial domain filtering method, system, device and medium for medium and high orbit anti-interference satellite-borne navigation receivers, which can make full use of the prior knowledge of the special scenario of medium and high orbit satellite-borne navigation receivers, and design a special anti-interference method for medium and high orbit satellite-borne navigation receivers for this specific scenario.

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

[0008] In a first aspect, the present invention provides a spatial domain filtering method for a satellite-borne navigation receiver, which comprises the following steps:

[0009] Obtain the host satellite position and navigation satellite position of this epoch;

[0010] The arrival direction and power attenuation coefficient of the navigation signal are estimated using the obtained host satellite position and navigation satellite position of the current epoch;

[0011] The beamforming weight coefficient is obtained by calculation or table lookup using the arrival direction and power attenuation coefficient of the navigation signal;

[0012] A combined signal is obtained according to the beamforming weight coefficient and the received navigation signal, and is output for subsequent processing.

[0013] Furthermore, the method for obtaining the host satellite position of the current epoch is: determining the host satellite position of the current epoch by using a navigation signal in space received by a navigation antenna array carried by the host satellite.

[0014] Furthermore, the method for determining the position of the host satellite in the current epoch by using the navigation signal in space received by the navigation antenna array carried by the host satellite comprises:

[0015] Using the navigation antenna array of the host satellite to receive navigation signals in space;

[0016] Determine whether the motion state of the host satellite in the previous epoch is reliable based on the received navigation signal:

[0017] If the motion state is reliable, the motion state of the host satellite in the previous epoch is used to predict the position of the host satellite in the current epoch;

[0018] Otherwise, the host satellite's pre-stored orbital information is used to predict the host satellite's position in this epoch.

[0019] Furthermore, the method for acquiring the position of the navigation satellite is: obtaining the position of the navigation satellite by predicting the ephemeris of the navigation satellite.

[0020] Further, the method of calculating or looking up a table to obtain a beamforming weight coefficient by using the navigation signal arrival direction and the power attenuation coefficient includes:

[0021] Searching in a weight coefficient lookup table whether there is a corresponding beamforming weight coefficient according to the arrival direction of the navigation signal and the signal power attenuation coefficient;

[0022] If yes, the beamforming weight coefficient is obtained by looking up the table;

[0023] Otherwise, the beamforming weight coefficient is calculated according to the arrival direction and power attenuation coefficient of the navigation signal, and the calculated beamforming weight coefficient is stored in the weight coefficient lookup table according to the arrival direction of the navigation satellite and the signal power attenuation coefficient.

[0024] Further, the method of calculating the beamforming weight coefficient according to the arrival direction and the power attenuation coefficient of the navigation signal, and storing the calculated beamforming weight coefficient in the weight coefficient lookup table according to the arrival direction of the navigation satellite and the signal power attenuation coefficient includes:

[0025] Calculate the direction vector of the receiving antenna array according to the arrival direction of the navigation signal;

[0026] Calculate the spatial interference power distribution matrix;

[0027] Calculate Lagrange multipliers based on the spatial interference power distribution matrix, the power attenuation coefficient and the direction vector;

[0028] The beamforming weight coefficient is calculated according to the Lagrange multiplier, the power attenuation coefficient and the direction vector;

[0029] The beamforming weight coefficients are stored in a weight coefficient lookup table according to the navigation signal arrival direction and the signal power attenuation coefficient.

[0030] Further, the method for calculating the Lagrange multiplier according to the spatial interference power distribution matrix, the power attenuation coefficient and the direction vector includes:

[0031] ① Perform eigenvalue decomposition on the spatial interference power distribution matrix to obtain the eigenvector matrix and eigenvalue matrix;

[0032] ② Set the number of iterations t = 1 and the initial value of the Lagrange multiplier μ 0 and amplitude difference threshold δ;

[0033] ③ Calculate the intermediate vector q based on the eigenvector matrix and the direction vector of the navigation signal;

[0034] ④ According to the intermediate vector q and the power attenuation coefficient, calculate the characteristic polynomial g(μ 0 ) and characteristic polynomial derivative g′(μ 0 );

[0035] ⑤ If the characteristic polynomial g(μ 0 )<0, then update the initial value of the Lagrange multiplier, μ t =μ t-1 -g(μ t-1 ) / g′(μ t-1 ), otherwise the iteration stops and the Lagrange multiplier is directly returned to 0;

[0036] ⑥If |μ t -μ t-1 |<δ, then go to step ⑧, otherwise calculate the characteristic polynomial g(μ t ) and characteristic polynomial derivative g′(μ t );

[0037] ⑦ Update μ t+1 =μ t -g(μ t ) / g′(μ t ),

[0038] ⑧ Update t = t + 1 and go to step ⑥;

[0039] ⑨Return to μ t Get the Lagrange multiplier for what you want.

[0040] In a second aspect, the present invention provides a spatial filtering system for a satellite-borne navigation receiver, comprising:

[0041] A position acquisition unit, used to acquire the host satellite position and navigation satellite position of this epoch;

[0042] A navigation signal information acquisition unit, used to estimate the arrival direction and power attenuation coefficient of the navigation signal using the obtained host satellite position and navigation satellite position of the current epoch;

[0043] A beamforming weight coefficient acquisition unit is used to calculate or look up a table to obtain a beamforming weight coefficient using the navigation signal arrival direction and power attenuation coefficient;

[0044] The combined signal acquisition unit is used to obtain the combined signal according to the beamforming weight coefficient and the received navigation signal correlation, and output it for subsequent processing.

[0045] In a third aspect, the present invention provides a processing device, which includes at least a processor and a memory, wherein the memory stores a computer program, and when the processor runs the computer program, the processor executes the steps of the spatial domain filtering method of the satellite-borne navigation receiver.

[0046] In a fourth aspect, the present invention provides a computer storage medium having computer-readable instructions stored thereon, wherein the computer-readable instructions can be executed by a processor to implement the steps of the spatial domain filtering method according to the satellite-borne navigation receiver.

[0047] Since the present invention adopts the above technical scheme, it has the following advantages: the spatial domain filtering method adopted by the present invention calculates the Lagrange multiplier through an iterative method and then determines the beamforming weight coefficient. It can be seen from the simulation results that the spatial domain filtering method proposed by the present invention can effectively improve the signal-to-interference ratio.

[0048] Therefore, the method can be widely used in the field of radio navigation technology, especially in the field of anti-interference of medium and high orbit satellite navigation receivers. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Throughout the accompanying drawings, the same reference numerals are used to represent the same components. In the accompanying drawings:

[0050] Figure 1 This is a typical scene diagram for current medium and high orbit satellite navigation receivers;

[0051] Figure 2 It is a simplified flow chart of a spatial domain filtering method for a medium- and high-orbit anti-interference satellite-borne navigation receiver in an embodiment of the present invention;

[0052] Figure 3 It is a flow chart of a spatial domain filtering method for a medium- and high-orbit anti-interference satellite-borne navigation receiver in an embodiment of the present invention;

[0053] Figure 4 is a Lagrange multiplier calculation method in an embodiment of the present invention;

[0054] Figure 5 is an average signal-to-interference ratio gain diagram of different spatial domain filtering algorithms with different interference-to-noise ratios and different numbers of interference sources in an embodiment of the present invention;

[0055] Figure 6 It is a structural diagram of a spatial filtering system for a medium- and high-orbit anti-interference satellite-borne navigation receiver in an embodiment of the present invention. DETAILED DESCRIPTION

[0056] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0057] See also Figure 1 , which is a typical scenario diagram of medium- and high-orbit satellite-borne navigation receivers. Among them, medium- and high-orbit satellites refer to satellites located in and above the navigation satellite orbit and below the geosynchronous orbit satellite. The host satellite in the medium- and high-orbit is equipped with a highly sensitive satellite-borne navigation receiver and a multi-element uniform circular array antenna to receive the main lobe leakage signal and side lobe signal from the navigation satellite on the other side of the earth for navigation positioning and timing. At the same time, interference signals from the ground will also be received. The interference signal mainly refers to the intentional or unintentional suppression interference and deceptive interference signals from the interference source on the ground in the navigation signal frequency band transmitted by the navigation satellite. Compared with traditional ground interference, this interference signal has the following characteristics:

[0058] 1. The number of interference sources of interference signals is huge and widely distributed. Since this typical scenario is an on-orbit scenario of a medium- and high-orbit navigation receiver, it is more than 20,000 kilometers away from the ground and almost half of the earth can be seen, and there may be interference sources that interfere with the navigation signal.

[0059] 2. There are many types of interference signals. Since interference sources are widely distributed, there are many types, including suppression interference and deception interference. Among them, suppression interference can be divided into narrowband interference and broadband interference.

[0060] 3. The interference signal power is low. Since this typical scenario is far away from the ground, the arrival power of the interference signal emitted by the general interference source is at most 15dB higher than the thermal noise.

[0061] These characteristics lead to the fact that the traditional anti-interference methods for ground-based navigation receivers in existing public documents and patents have general or inapplicable implementation effects. In view of this, the present invention proposes a spatial domain filtering method for medium and high orbit anti-interference satellite-borne navigation receivers.

[0062] Example 1

[0063] like Figure 2 As shown, this embodiment is based on Figure 1 Taking the typical scenario of the medium- and high-orbit satellite-borne navigation receiver shown in the figure as an example, a spatial domain filtering method for a medium- and high-orbit anti-interference satellite-borne navigation receiver provided in this embodiment is introduced, which includes the following steps:

[0064] S1. Obtain the host satellite position and navigation satellite position of this epoch;

[0065] S2, using the obtained host satellite position and navigation satellite position of the current epoch to estimate the arrival direction and power attenuation coefficient of the navigation signal;

[0066] S3. Calculate or look up a table to obtain a beamforming weight coefficient using the navigation signal arrival direction and power attenuation coefficient;

[0067] S4. Obtain a combined signal according to the beamforming weight coefficient and the received navigation signal, and output it for subsequent processing.

[0068] In a preferred embodiment, Figure 3 As shown, in the above step S1, the method for obtaining the host satellite position of the current epoch is: determining the host satellite position of the current epoch by using the navigation signal in space received by the navigation antenna array carried by the host satellite.

[0069] Specifically, the steps include:

[0070] Using the navigation antenna array of the host satellite to receive navigation signals in space;

[0071] Determine whether the motion state of the host satellite in the previous epoch is reliable based on the received navigation signal:

[0072] If the motion state is reliable, the motion state of the host satellite in the previous epoch is used to predict the position of the host satellite in the current epoch;

[0073] Otherwise, the host satellite's pre-stored orbital information is used to predict the host satellite's position in this epoch.

[0074] In a preferred embodiment, the navigation signal is a superposition of a main lobe leakage signal or a side lobe signal transmitted by a navigation satellite, an interference signal from the direction of the earth, and instrument thermal noise.

[0075] In a preferred embodiment, the motion state of the host satellite in the previous epoch is obtained by the navigation solution in the previous epoch.

[0076] In a preferred embodiment, in the above step S1, the method for obtaining the navigation satellite position of the current epoch is: obtaining the navigation satellite position by predicting the ephemeris of the navigation satellite. The prediction method is well known to those skilled in the art, and the present invention will not be described in detail here.

[0077] In a preferred embodiment, the arrival direction of the navigation signal includes two dimensions: an off-axis angle and a rotation angle, and the estimation method is a common method in the art.

[0078] In a preferred embodiment, in the above step S2, the power attenuation coefficient of the navigation signal is denoted as ξ, which satisfies:

[0079]

[0080] Among them, |f(θ s )| is the square root of the receiving antenna gain in the direction of arrival of the navigation signal, γ is the preset satellite navigation receiver sensitivity, σ is the standard deviation of thermal noise, P r is the signal power, which can be estimated by the following formula:

[0081]

[0082] Among them G t and G r are the transmitting antenna gain and the receiving antenna gain, respectively, and f c is the carrier center frequency, c is the speed of light, d is the distance between the host satellite and the navigation satellite, and the host satellite position coordinates are marked as (x s ,y s ,z s ), and mark the navigation satellite position coordinates as (x d ,y d ,z d ),satisfy

[0083]

[0084] In a preferred embodiment, the above step S3 includes the following steps:

[0085] S31, searching in the weight coefficient lookup table whether there is a corresponding beamforming weight coefficient according to the navigation signal arrival direction and the signal power attenuation coefficient, if yes, proceed to step S32, otherwise proceed to step S33;

[0086] S32, searching in a weight coefficient lookup table to obtain a beamforming weight coefficient corresponding to the navigation signal arrival direction and the signal power attenuation coefficient;

[0087] S33. Calculate the beamforming weight coefficient according to the arrival direction and power attenuation coefficient of the navigation signal, and store the calculated beamforming weight coefficient in a weight coefficient lookup table according to the arrival direction of the navigation satellite and the signal power attenuation coefficient.

[0088] In a preferred embodiment, the above step S33 includes the following steps:

[0089] S331, calculating the direction vector of the receiving antenna array according to the arrival direction of the navigation signal;

[0090] S332, calculating the spatial interference power distribution matrix;

[0091] S333, calculating Lagrange multipliers according to the spatial interference power distribution matrix, the power attenuation coefficient and the direction vector;

[0092] S334, calculating a beamforming weight coefficient according to the Lagrange multiplier, the power attenuation coefficient and the direction vector;

[0093] S335. Store the beamforming weight coefficient into a weight coefficient lookup table according to the navigation signal arrival direction and the signal power attenuation coefficient.

[0094] In a preferred embodiment, in the above step S331, the antenna array direction vector is recorded as a s ,satisfy

[0095]

[0096] Where j is a complex unit, N is the number of elements of the uniform circular array antenna (usually 4, 6 or 8), θ s and are the off-axis angle and rotation angle of the arrival direction of the navigation signal.

[0097] In a preferred embodiment, in the above step S332, the spatial interference power distribution matrix is ​​recorded as D, satisfying

[0098]

[0099] Wherein, J0(·) is the zero-order modified Bessel function. If the radius of the earth is r, the orbit height is h, θ0 = arcsin(r / (r+h)), p(θ) is the probability density distribution of the off-axis angle of the arrival direction of the interference signal, which can be but is not limited to

[0100]

[0101] Among them, a=r / (h+2r), b=h / (h+2r).

[0102] In a preferred embodiment, Figure 4 As shown, the above step S333 specifically includes:

[0103] ① Perform eigenvalue decomposition on the spatial interference power distribution matrix to obtain the eigenvector matrix and eigenvalue matrix;

[0104] Among them, the eigenvector matrix and eigenvalue matrix are recorded as Q and S, and there are

[0105] D=QSQ T

[0106] Among them, S is a diagonal matrix, and the diagonal elements are the eigenvalues ​​of D, denoted by λ i ,i=1,2,…,N;

[0107] ② Set the number of iterations t = 1 and the initial value of the Lagrange multiplier μ 0 and amplitude difference threshold δ, where μ 0 Generally take 0 + ;

[0108] ③ According to the eigenvector matrix and the direction vector of the navigation signal, calculate the intermediate vector q, which satisfies

[0109] q=Q T as

[0110] ④ According to the intermediate vector q and the power attenuation coefficient, calculate the characteristic polynomial g(μ 0 ) and characteristic polynomial derivative g′(μ 0 );

[0111] Among them, the characteristic polynomial g(μ) satisfies

[0112]

[0113] The characteristic polynomial derivative g′(μ) satisfies

[0114]

[0115] Among them, q i is the i-th element of the intermediate vector q;

[0116] ⑤ If the characteristic polynomial g(μ 0 )<0, then update the initial value of the Lagrange multiplier, μ t =μ t-1 -g(μ t-1 ) / g′(μ t-1 ), otherwise the iteration stops and the Lagrange multiplier is directly returned to 0;

[0117] ⑥If |μ t -μ t-1 |<δ, then go to step ⑧, otherwise calculate the characteristic polynomial g(μ t ) and characteristic polynomial derivative g′(μ t );

[0118] ⑦ Update μ t+1 =μ t -g(μ t ) / g′(μ t ),

[0119] ⑧ Update t = t + 1 and go to step ⑥;

[0120] ⑨Return to μ t Get the Lagrange multiplier for what you want.

[0121] In a preferred embodiment, in the above step S334, the beamforming weight coefficient is recorded as w, satisfying

[0122]

[0123] In a preferred embodiment, in the above step S4, it is assumed that the signal received by each antenna array element is x i (t), i = 1, 2, ..., N, the combined signal x(t) satisfies:

[0124]

[0125] Among them, w i To obtain the i-th element of the beamforming weight coefficient vector w.

[0126] The essence of the method and system according to the present invention is to use the spatial diversity characteristics of navigation signals and interference to perform spatial filtering. Figure 5 As shown, under the conditions of broadband interference of 20000km orbit height of the satellite navigation receiver, 8 elements of the uniform circular array antenna, 53° off-axis angle of the navigation signal, 1 to 20 uniformly distributed interference sources from the ground and interference to noise ratio (interference to noise ratio) of -20 to 10dB, the simulation results show that the average signal to interference power ratio (signal to interference ratio) gain after filtering is significantly improved compared with the power inversion (PI) and minimum variance distortionless response (MVDR) commonly used in this field (when the number of broadband interference sources is 20, the advantage of the patented method reaches about 10dB to 40dB), and the average effect of the patented spatial domain filtering method is significantly better than the two traditional commonly used spatial domain filtering anti-interference methods.

[0127] Example 2

[0128] The above-mentioned embodiment 1 provides a spatial domain filtering method for medium and high orbit anti-interference satellite-borne navigation receivers. Correspondingly, this embodiment provides a spatial domain filtering system for medium and high orbit anti-interference satellite-borne navigation receivers. The system provided in this embodiment can implement a spatial domain filtering method for medium and high orbit anti-interference satellite-borne navigation receivers in embodiment 1, and the system can be implemented by software, hardware, or a combination of software and hardware. For example, the system may include integrated or separate functional modules or functional units to perform the corresponding steps in each method of embodiment 1. Since the system of this embodiment is basically similar to the method embodiment, the process described in this embodiment is relatively simple, and the relevant parts can refer to the partial description of embodiment 1. The embodiment of the system provided in this embodiment is only schematic.

[0129] This embodiment provides a spatial filtering method for a medium- and high-orbit anti-interference satellite-borne navigation receiver, which includes:

[0130] A position acquisition unit, used to acquire the host satellite position and navigation satellite position of this epoch;

[0131] A navigation signal information acquisition unit, used to estimate the arrival direction and power attenuation coefficient of the navigation signal using the obtained host satellite position and navigation satellite position of the current epoch;

[0132] A beamforming weight coefficient acquisition unit is used to calculate or look up a table to obtain a beamforming weight coefficient using the navigation signal arrival direction and power attenuation coefficient;

[0133] The combined signal acquisition unit is used to obtain the combined signal according to the beamforming weight coefficient and the received navigation signal correlation, and output it for subsequent processing.

[0134] In a preferred embodiment, Figure 6 As shown, the position acquisition unit includes:

[0135] The RF front end B1 has an input connected to the RF navigation signal received by the uniform circular array antenna, and an output connected to the judgment module B2 and the correlation module B9, and is used to down-convert the received RF navigation signal into a baseband signal;

[0136] The judgment module B2 has an input connected to the RF front end B1 and the motion state of the host satellite in the previous epoch, and an output connected to the host satellite prediction module B3, and is used to judge whether the motion state of the host satellite in the previous epoch is reliable. The output command signal 1 represents reliability, and the output command signal 0 represents unreliability;

[0137] The host satellite prediction module B3 has an input connected to the judgment module B2, the motion state of the host satellite in the previous epoch and the pre-stored orbit information, and an output connected to the navigation satellite prediction module B4, which is used to predict the motion state of the host satellite in the current epoch according to the motion state of the host satellite in the previous epoch, the pre-stored orbit information and the command signal. If the command signal is 0, the pre-stored orbit information is used for prediction; if the command signal is 1, the motion state of the host satellite in the previous epoch is used for prediction;

[0138] The navigation satellite prediction module B4 has its input connected to the host satellite prediction module B3 and the navigation satellite ephemeris, and its output connected to the signal arrival direction estimation module B5, and is used to predict the navigation satellite position using the navigation satellite ephemeris.

[0139] In a preferred embodiment, the navigation signal information acquisition unit includes:

[0140] The signal arrival direction estimation module B5 has its input connected to the host satellite prediction module B3 and the navigation satellite prediction module B4, and its output connected to the judgment module B6, the weight coefficient calculation module B7 and the weight coefficient lookup table B8, and is used to calculate the signal arrival direction and the signal power attenuation coefficient according to the host satellite position output by the host satellite prediction module B3 and the navigation satellite position output by the navigation satellite prediction module B4.

[0141] In a preferred embodiment, the beamforming weight coefficient acquisition unit includes:

[0142] The judging module B6 has an input connected to the signal arrival direction estimation module B5 and the weight coefficient lookup table B8, and an output connected to the weight coefficient calculation module B7, which is used to judge whether there is a weight coefficient at the index in the weight coefficient lookup table B8 according to the signal arrival direction and the power attenuation coefficient output by the signal arrival direction estimation module B5, and if so, the output instruction signal is 1, otherwise it is 0;

[0143] A weight coefficient calculation module B7, whose input is connected to the signal arrival direction estimation module B5 and the judgment module B6, and whose output is connected to the weight coefficient lookup table B8, is used to calculate the beamforming weight coefficient according to the signal arrival direction and power attenuation coefficient of the signal arrival direction estimation module B5 and the command signal of the judgment module B6, and if the command signal is 0, it is calculated, otherwise it is not calculated;

[0144] The weight coefficient lookup table B8 has its input connected to the signal arrival direction estimation module B5, the judgment module B6 and the weight coefficient calculation module B7, and its output connected to the judgment module B6 and the related module B9. It is used to look up or insert the weight coefficient of the corresponding position according to the signal arrival direction and the power attenuation coefficient of the signal arrival direction estimation module B5 as an index. If the instruction signal is 1, the table is looked up, otherwise it is inserted, and the judgment module B6 and the related module B9 are output.

[0145] In a preferred embodiment, the combined signal acquisition unit includes:

[0146] The correlation module B9 has its input connected to the weight coefficient lookup table B8 and the RF front end B1, and outputs the final combined signal. It is used to perform correlation operations based on the baseband signal output by the RF front end B1 and the weight coefficient output by the weight coefficient lookup table B8, and output the combined signal.

[0147] Example 3

[0148] This embodiment provides a processing device corresponding to the spatial domain filtering method for medium and high orbit anti-interference satellite-borne navigation receivers provided in this embodiment 1. The processing device can be a processing device for a client, such as a mobile phone, a laptop computer, a tablet computer, a desktop computer, etc., to execute the method of embodiment 1.

[0149] The processing device includes a processor, a memory, a communication interface and a bus, and the processor, the memory and the communication interface are connected through the bus to complete mutual communication. The memory stores a computer program that can be run on the processor, and the processor executes the spatial domain filtering method for medium and high orbit anti-interference satellite navigation receivers provided in this embodiment 1 when running the computer program.

[0150] In some embodiments, the memory may be a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk memory.

[0151] In other embodiments, the processor may be a central processing unit (CPU), a digital signal processor (DSP), or other general-purpose processors of various types, which are not limited herein.

[0152] Example 4

[0153] The spatial domain filtering method for medium and high orbit anti-interference satellite-borne navigation receivers of this embodiment 1 can be specifically implemented as a computer program product, which may include a computer-readable storage medium carrying computer-readable program instructions for executing the spatial domain filtering method for medium and high orbit anti-interference satellite-borne navigation receivers described in this embodiment 1.

[0154] Computer readable storage media can be tangible devices that hold and store instructions used by instruction execution devices. Computer readable storage media can be, for example, but not limited to, electronic storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any combination thereof.

[0155] It should be noted that the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the systems, methods and computer program products according to multiple embodiments of the present application. Each box in the flowchart or block diagram may represent a module, a program segment or a part of the code, and the module, program segment or a part of the code contains one or more executable instructions for implementing the specified logical functions.

[0156] Those skilled in the art may also make other changes within the spirit of the present invention. Of course, these changes made according to the spirit of the present invention should be included in the scope of protection required by the present invention.

[0157] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A spatial filtering method for a medium- and high-orbit satellite navigation receiver, characterized in that: The following steps are involved: Obtain the host satellite position and navigation satellite position of this epoch; The arrival direction and power attenuation coefficient of the navigation signal are estimated using the obtained host satellite position and navigation satellite position of the current epoch; The beamforming weight coefficient is obtained by calculation or table lookup using the arrival direction and power attenuation coefficient of the navigation signal; A combined signal is obtained according to the beamforming weight coefficient and the received navigation signal, and output for subsequent processing; The method of calculating or looking up a table to obtain a beamforming weight coefficient by using the navigation signal arrival direction and the power attenuation coefficient comprises: Searching in a weight coefficient lookup table whether there is a corresponding beamforming weight coefficient according to the arrival direction of the navigation signal and the signal power attenuation coefficient; If yes, the beamforming weight coefficient is obtained by looking up the table; Otherwise, the beamforming weight coefficient is calculated according to the arrival direction and power attenuation coefficient of the navigation signal, and the calculated beamforming weight coefficient is stored in the weight coefficient lookup table according to the arrival direction of the navigation satellite and the signal power attenuation coefficient; The method of calculating a beamforming weight coefficient according to an arrival direction and a power attenuation coefficient of a navigation signal, and storing the calculated beamforming weight coefficient in a weight coefficient lookup table according to the arrival direction of the navigation satellite and the signal power attenuation coefficient, comprises: Calculate the direction vector of the receiving antenna array according to the arrival direction of the navigation signal; Calculate the spatial interference power distribution matrix; Calculate Lagrange multipliers based on the spatial interference power distribution matrix, the power attenuation coefficient and the direction vector; The beamforming weight coefficient is calculated according to the Lagrange multiplier, the power attenuation coefficient and the direction vector; The beamforming weight coefficients are stored in a weight coefficient lookup table according to the navigation signal arrival direction and the signal power attenuation coefficient.

2. The spatial domain filtering method for a medium- and high-orbit satellite-borne navigation receiver according to claim 1, characterized in that: The method for obtaining the host satellite position of the current epoch is: determining the host satellite position of the current epoch by using a navigation signal in space received by a navigation antenna array carried by the host satellite.

3. The spatial domain filtering method for a medium- and high-orbit satellite-borne navigation receiver according to claim 2, characterized in that: The method for determining the position of the host satellite in the current epoch by using the navigation signal in space received by the navigation antenna array carried by the host satellite comprises: Utilize the navigation antenna array of the host satellite to receive navigation signals in space; Determine whether the motion state of the host satellite in the previous epoch is reliable based on the received navigation signal: If the motion state is reliable, the motion state of the host satellite in the previous epoch is used to predict the position of the host satellite in the current epoch; Otherwise, the host satellite's pre-stored orbital information is used to predict the host satellite's position in this epoch.

4. The spatial domain filtering method for a medium- and high-orbit satellite-borne navigation receiver according to claim 1, characterized in that: The method for acquiring the position of the navigation satellite is: obtaining the position of the navigation satellite by predicting the ephemeris of the navigation satellite.

5. The spatial domain filtering method for a medium- and high-orbit satellite-borne navigation receiver according to claim 1, characterized in that: The method for calculating the Lagrange multiplier according to the spatial interference power distribution matrix, the power attenuation coefficient and the direction vector comprises: ① Perform eigenvalue decomposition on the spatial interference power distribution matrix to obtain the eigenvector matrix and eigenvalue matrix; ② Set the number of iterations , the initial value of the Lagrange multiplier Sum Amplitude Difference Threshold ; ③ Calculate the intermediate vector according to the eigenvector matrix and the direction vector of the navigation signal ; ④ According to the intermediate vector and the power attenuation coefficient, calculate the characteristic polynomial and the characteristic polynomial derivative ; ⑤ If the characteristic polynomial , then the initial value of the Lagrange multiplier is updated, , otherwise the iteration stops and the Lagrange multiplier is directly returned to 0; ⑥ If , then go to step ⑨, otherwise calculate the characteristic polynomial and the characteristic polynomial derivative ; ⑦ Update , ⑧ Update , proceed to step ⑥; ⑨ Return Get the Lagrange multiplier for what you want.

6. A spatial filtering system for a medium- and high-orbit satellite navigation receiver, characterized in that: include: A position acquisition unit, used to acquire the host satellite position and navigation satellite position of this epoch; A navigation signal information acquisition unit, used to estimate the arrival direction and power attenuation coefficient of the navigation signal using the obtained host satellite position and navigation satellite position of the current epoch; A beamforming weight coefficient acquisition unit is used to calculate or look up a table to obtain a beamforming weight coefficient using the navigation signal arrival direction and power attenuation coefficient; A combined signal acquisition unit, used to obtain a combined signal according to the beamforming weight coefficient and the received navigation signal, and output it for subsequent processing; The step of calculating or looking up a table to obtain a beamforming weight coefficient by using the navigation signal arrival direction and the power attenuation coefficient includes: Searching in a weight coefficient lookup table whether there is a corresponding beamforming weight coefficient according to the arrival direction of the navigation signal and the signal power attenuation coefficient; If yes, the beamforming weight coefficient is obtained by looking up the table; Otherwise, the beamforming weight coefficient is calculated according to the arrival direction and power attenuation coefficient of the navigation signal, and the calculated beamforming weight coefficient is stored in the weight coefficient lookup table according to the arrival direction of the navigation satellite and the signal power attenuation coefficient; The beamforming weight coefficient is calculated according to the arrival direction and power attenuation coefficient of the navigation signal, and the calculated beamforming weight coefficient is stored in the weight coefficient lookup table according to the arrival direction of the navigation satellite and the signal power attenuation coefficient, including: Calculate the direction vector of the receiving antenna array according to the arrival direction of the navigation signal; Calculate the spatial interference power distribution matrix; Calculate Lagrange multipliers based on the spatial interference power distribution matrix, the power attenuation coefficient and the direction vector; The beamforming weight coefficient is calculated according to the Lagrange multiplier, the power attenuation coefficient and the direction vector; The beamforming weight coefficients are stored in a weight coefficient lookup table according to the navigation signal arrival direction and the signal power attenuation coefficient.

7. A processing device, comprising at least a processor and a memory, wherein a computer program is stored in the memory, wherein: When the processor runs the computer program, the processor executes the steps of implementing the spatial domain filtering method of the medium- and high-orbit satellite-borne navigation receiver as described in any one of claims 1 to 5.

8. A computer storage medium, characterized in that Computer-readable instructions are stored thereon, and the computer-readable instructions can be executed by a processor to implement the steps of the spatial domain filtering method for a medium- and high-orbit satellite-borne navigation receiver according to any one of claims 1 to 5.

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