A satellite navigation controlled wireless field simulation design method

Abstract

The present invention provides a satellite navigation controlled wireless field simulation design method, which relates to the field of satellite navigation simulation test. The present invention includes: defining the size of the central test area and the primary reflection level index, determining the equivalent spacing distance and the number of antennas of the antenna array; determining the number of channels of the satellite navigation simulation source and the number of channels of the channel simulation module; defining the optimized feature point in the central test area, setting the field intensity of the synthetic plane wave of the origin of the central test area and the transformation matrix from each antenna to the optimized feature point, and obtaining the relationship between the target field vector, the steering vector, and the transformation matrix; solving the minimization problem, the satellite navigation simulation source and the channel simulator generate related satellite navigation signals according to the steering vector to construct a simulated satellite navigation controlled wireless field that meets the requirements. The present invention can finely control the signal field structure formed by satellite navigation, realize the rich wave direction simulation of the satellite navigation signal, and can be used for satellite navigation anti-interference test.

Description

Technical Field

[0001] The invention belongs to the technical field of satellite navigation simulation test, and in particular relates to a simulation design method of a satellite navigation controlled wireless field for satellite navigation test. Background Art

[0002] With the official opening of the BeiDou-3 global satellite navigation system, my country's satellite navigation industry has entered a new stage of rapid development. The downlink signal of the existing satellite navigation system is very weak, and various application terminals inevitably face complex electromagnetic environments such as intentional and unintentional interference, which leads to huge challenges for the safe application of satellite navigation. The means of countering interference and anti-interference of satellite navigation terminals are constantly evolving, which puts higher requirements on the construction of satellite navigation wireless field environment for testing.

[0003] Existing satellite navigation wireless field environment simulation methods have their own limitations. In terms of satellite navigation signal field simulation, traditional satellite navigation indoor controlled wireless field construction uses fixed satellites or slide rails to achieve dynamic fields, which has the problems of fixed scenes and limited simulation time. How to build a controlled, realistic, and complex wireless field simulation environment to achieve full-frequency, multi-directional, changeable, and repeatable satellite navigation signal fields is a huge challenge. Summary of the invention

[0004] In order to realize a satellite navigation signal field with full frequency, multiple directions, changeable and repeatable, the present invention provides a controlled wireless field simulation design method for satellite navigation test. The method adopts the principle of antenna array and signal superposition, and can construct a simulated satellite navigation signal field with rich directions and controllable, and can simplify the design according to the far-field conditions that can be achieved in the microwave darkroom, so as to realize the construction of satellite navigation controlled wireless field environment under different costs and supporting facilities. It not only provides a powerful tool for satellite navigation testing, but also provides a theoretical basis for the construction of controlled wireless field environment under subsequent low-orbit enhancement, and can promote the continuous iteration and upgrading of related navigation interference and anti-interference technologies.

[0005] The technical solution adopted by the present invention is:

[0006] A satellite navigation controlled wireless field simulation design method comprises the following steps:

[0007] (1) According to the operating frequency , define the size of the central test area and the primary reflection level index to be achieved, according to the spatial sampling theorem, based on the size of the central test area, determine the equivalent spacing distance of the antenna array, and determine the number of antennas to be M, the equivalent spacing distance of the antenna array is less than , Corresponding operating frequency wavelength;

[0008] (2) According to the number of satellites of the satellite navigation system to be simulated, the number of channels K of the satellite navigation simulation source is determined, thereby determining the number of channels of the channel simulation module to be K×M;

[0009] (3) Delineate N optimized feature points in the central test area , n=1,2,3,...,N, and the field strength of the synthetic plane wave at the origin of the central test area is set to , each optimized feature point Satellite The target field vector generated by the approximate far-field plane wave , the transformation matrix from each antenna to the optimized feature point is ,in for The elements in Indicates transmitting antennas, Indicates optimized feature points; each simulation source is The steering vector from the antenna to the target point along the direction of the propagation vector is ,in Define the direction of arrival in azimuth and elevation, is polarization; target field vector, steering vector , transformation matrix The relationship is ,in Represents the spatial dimension;

[0010] (4) Solve the minimization problem:

[0011] ;

[0012] in, , using the Moore-Penrose pseudoinverse Solve, where ,get:

[0013] ;

[0014] in, For each frequency and each angle of arrival The steering vectors are obtained independently, After linear superposition, a signal incident from any direction is formed; , represents the rearrangement formula of X matrix; superscript + represents the pseudo-inverse matrix of X matrix, superscript T represents the transposed matrix of X, and superscript H represents the Hermite matrix of X;

[0015] The satellite navigation simulation source and the channel simulator generate relevant satellite navigation signals according to the steering vector to construct a simulated satellite navigation controlled wireless field that meets the requirements.

[0016] Furthermore, the hardware environment of the satellite navigation controlled wireless field includes a satellite navigation simulation source, a channel simulator, a transmitting antenna array, and a controlled wireless field microwave darkroom.

[0017] Furthermore, if the transmitting antenna array of the satellite navigation controlled wireless field meets the far-field condition constraints, the central test area field amplitude uniformity condition constraints, the amplitude difference constraint between the center and the edge, and the phase difference constraint between the center and the edge, the channel simulator is simplified to form a satellite navigation signal simulator in which each channel simulates one satellite, and the broadcast satellite navigation signal no longer undergoes spatial field synthesis. The cross-regional movement of the satellite is simulated by combining the simulated source satellite motion simulation with the spatial domain switching of the antennas corresponding to different simulated source channels. The spatial direction change caused by the orbital motion of the satellite is simulated by switching from one adjacent antenna to another, thereby achieving continuous and seamless changes in the satellite motion trajectory and simulating the satellite navigation controlled wireless field.

[0018] Furthermore, the far-field condition is constrained as follows:

[0019] ,

[0020] in, is the distance between a single transmitting antenna and the receiving antenna under test in the microwave darkroom, is the transmitting antenna aperture, is the receiving antenna aperture, is the working wavelength;

[0021] The field amplitude uniformity condition constraint of the central test area is:

[0022] ,

[0023] in, The level amplitude changes in the central test area;

[0024] The amplitude difference constraint between the center and the edge is:

[0025] ,

[0026] in, is the amplitude difference between the center and the edge, is the center difference between the transmitting antenna and the receiving antenna;

[0027] The phase difference between the center and the edge is constrained as follows:

[0028] ,

[0029] in, is the array antenna element factor, is the phase difference value.

[0030] The beneficial effects of the present invention are:

[0031] 1. The present invention proposes a satellite navigation controlled wireless field simulation design method, which can be built based on existing equipment, is easy to implement, and is easy to use and practical.

[0032] 2. The present invention can finely control the signal field structure formed by satellite navigation, realize the rich wave direction simulation of satellite navigation signals comparable to the real environment, and is particularly suitable for satellite navigation anti-interference testing.

[0033] 3. The present invention can simplify the structure according to the far-field conditions of the darkroom and the field constraints of the quiet zone, and has the characteristics of being customizable and easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a block diagram of the satellite navigation controlled wireless field environment construction of the present invention;

[0035] Figure 2 It is a block diagram of the satellite navigation controlled wireless field calculation principle of the present invention;

[0036] Figure 3 It is a schematic diagram of the relationship between the array transmitting antenna and the receiving array antenna of the present invention. DETAILED DESCRIPTION

[0037] The present invention will be described in detail below with reference to the accompanying drawings by means of exemplary embodiments of the present invention. It should be noted that the following detailed description of the present invention is only for the purpose of illustration, and is not intended to limit the present invention.

[0038] A satellite navigation controlled wireless field simulation design method comprises the following steps:

[0039] (1) According to the operating frequency , define the size of the central test area (quiet zone) and the primary reflection level index to be achieved, and determine the equivalent spacing distance of the antenna array based on the size of the quiet zone according to the spatial sampling theorem, that is, the antenna equivalent spacing distance is less than , Corresponding operating frequency wavelength, and determine the number of antennas to be M;

[0040] (2) According to the number of satellites of the satellite navigation system to be simulated, the number of channels K of the satellite navigation simulation source is determined, thereby determining the number of channels of the channel simulation module to be K×M;

[0041] (3) Delineate N optimized feature points in the central test area , the field strength of the synthetic plane wave at the origin of the central test area is set to , each feature point Satellite The target field vector generated by the approximate far-field plane wave , the transformation matrix from each antenna to the optimized feature point ,in for The elements in Indicates transmitting antennas, Indicates Each simulation source is optimized through The steering vector from the antenna to the target point along the direction of the propagation vector is .in Define the Direction Of Arrival (DOA) in azimuth and elevation, respectively. is polarization. Target field vector, steering vector , transformation matrix The relationship is:

[0042] ,

[0043] in, Represents the spatial dimension.

[0044] (4) Solve the minimization problem:

[0045] ,

[0046] in, , using the Moore-Penrose pseudoinverse Solve, where ,get:

[0047] ,

[0048] in, For each frequency and each angle of arrival The steering vectors obtained independently can be linearly superimposed to form signals incident from any direction. At this point, the satellite navigation simulation source and the channel simulator can generate relevant satellite navigation signals based on the steering vectors to construct a simulation of a satellite navigation controlled wireless field that meets the requirements.

[0049] Among them, in order to realize the satellite navigation controlled wireless field, it is necessary to build the corresponding hardware environment, such as Figure 1As shown, it includes a satellite navigation simulation source 1, a channel simulator 2, a transmitting antenna 3, and a controlled wireless field microwave darkroom 4. According to the communication link of the satellite navigation system, a satellite navigation controlled wireless field is constructed. According to the size of the object under test in the wireless field, the equivalent spacing distance of the antenna array is determined according to the spatial sampling theorem, thereby determining the number of antenna arrays and the number of satellite navigation simulation source channels.

[0050] Satellite navigation controlled wireless field calculation principle block diagram Figure 2 The optimization solution of the satellite navigation controlled wireless field includes determining the optimized characteristic points of the central test area, setting the field strength of the origin of the central test area, constructing the target vector function and the steering vector field function, forming the target field, the steering vector and solving their minimization problems, thereby obtaining the steering vector field of the antenna array.

[0051] If the distance R between the transmitting antenna and the receiving antenna under test in the constructed microwave darkroom meets the far-field condition, the satellite navigation controlled wireless field can also be simplified in design. According to the design size of the microwave darkroom, the antenna aperture of the transmitting antenna array unit and the receiving antenna aperture of the object under test, it is judged whether the transmitting antenna array for constructing the satellite navigation controlled wireless field meets the far-field condition. If the far-field condition is met, in this case, verification calculations of the quiet zone field amplitude, the amplitude at the center of the test area and the phase difference value need to be performed. If it is further met, the channel simulator can be simplified to form a satellite navigation signal simulator in which each channel simulates a satellite. The broadcast satellite navigation signal can no longer be synthesized in the space field. The cross-regional movement of the satellite is simulated by combining the simulation of the simulated source satellite motion with the spatial division of the antennas corresponding to different simulated source channels. The simulation of the spatial direction change caused by the orbital motion of the satellite can be "switched" and "handed over" by an adjacent antenna to another antenna, thereby realizing the continuous and seamless change of the satellite motion trajectory, thereby simulating the satellite navigation controlled wireless field.

[0052] The conditions that need to be met for the simplified design of satellite navigation controlled wireless field are as follows:

[0053] Condition 1: Far-field condition constraint. The satellite navigation simulation signal transmitting antenna in the darkroom should maintain the far-field condition with the satellite navigation receiving antenna under test. Generally, the phase difference between the center and the edge is required to be △ϕ≤22.5° (π / 8). According to this requirement, the far-field condition selected by this method is ,in, is the distance between a single transmitting antenna and the receiving antenna under test in the microwave darkroom, is the transmitting antenna aperture, is the receiving antenna aperture, is the working wavelength;

[0054] Condition 2: The uniformity of the amplitude of the quiet area. For the test of the whole navigation terminal installed on a large carrier, the navigation performance test under the condition of the whole installation is usually carried out by partially cutting off the carrier or hoisting the whole carrier. The cutting tool is generally selected to be twice the length of the receiver antenna aperture to simulate the boundary conditions after the antenna is installed. Here, the level amplitude change in the scenic area is required to be ,So ;

[0055] Condition 3, the amplitude difference constraint between the center and the edge. To test the array antenna in the darkroom, the zenith center antenna is used as the test benchmark. It is required that the amplitude difference from the zenith transmitting antenna to the center and edge of the array antenna should be approximately equal or even negligible. According to the spatial fading law, the calculation is based on the zenith transmitting antenna in the center normal direction, such as Figure 3 , the amplitude difference between the center and the edge for:

[0056] ,

[0057] in, is the center difference between the transmitting antenna and the receiving antenna. The change is based on R / D as the variable, and the appropriate R / D value should be selected to make Meet design requirements;

[0058] Condition 4: Phase difference constraint between the center and the edge. Similar to condition 3, the normal distance between the edge unit and the center unit is also considered. The phase difference at is calculated as follows:

[0059] ,

[0060] in, is the array antenna element factor. For a 16-element antenna, the element factor is is 4. Phase difference The change is based on R / D as the variable, and the appropriate R / D value should be selected to make Meet design requirements.

[0061] This method can overcome the problems of uneven incoming wave directions, fixed and single scenes, and limited simulation time in existing satellite navigation infield tests, thereby realizing a full-frequency, multi-directional, changeable, and repeatable satellite navigation signal field.

[0062] The method can simplify the design to realize a simulated satellite channel composed of a transmitting antenna and its corresponding satellite navigation simulation source channel, simulate a satellite navigation satellite, and the broadcast satellite navigation signal no longer needs to be synthesized in space. The simulation of the spatial direction change of the satellite due to the orbital motion can be "switched" or "handed over" from one adjacent antenna to another, thereby realizing continuous and seamless changes in the satellite's motion trajectory.

[0063] In summary, the present invention can reduce the complexity of signal field simulation according to the far-field conditions of satellite navigation signals, construct and verify the corresponding microwave darkroom, and provide corresponding constraint conditions and calculation conditions. The present invention breaks through the difficulty of satellite navigation signal field simulation, establishes a complete set of satellite navigation signal controlled wireless field construction models, and provides theoretical basis and practical guidance for future satellite navigation and satellite navigation testing under low-orbit enhancement.

Claims

1. A satellite navigation controlled wireless field simulation method, characterized in that: The following steps are included: (1) According to the operating frequency , define the size of the central test area and the primary reflection level index to be achieved, and according to the spatial sampling theorem, determine the equivalent spacing distance of the antenna array based on the size of the central test area, and determine the number of antennas to be M. The equivalent spacing distance of the antenna array is less than , Corresponding operating frequency wavelength; (2) According to the number of satellites of the satellite navigation system to be simulated, the number of channels K of the satellite navigation simulation source is determined, thereby determining the number of channels of the channel simulation module to be K×M; (3) Delineate N optimized feature points in the central test area , n=1,2,3,...,N, and the field strength of the synthetic plane wave at the origin of the central test area is set to , each optimized feature point Satellite The target field vector generated by the approximate far-field plane wave , the transformation matrix from each antenna to the optimized feature point is ,in for The elements in Indicates transmitting antennas, Indicates optimized feature points; each simulation source is The steering vector transmitted from the antenna to the target point is ,in Define the direction of arrival in azimuth and elevation, is polarization; target field vector, steering vector , transformation matrix The relationship is ,in Represents the spatial dimension; (4) Solve the minimization problem: ； in, , using the Moore-Penrose pseudoinverse Solve, where ,get: ； in, For each frequency and each angle of arrival The steering vectors are obtained independently, After linear superposition, a signal incident from any direction is formed; , represents the rearrangement formula of X matrix; superscript + represents the pseudo-inverse matrix of X matrix, superscript T represents the transposed matrix of X, and superscript H represents the Hermite matrix of X; The satellite navigation simulation source and the channel simulator generate relevant satellite navigation signals according to the steering vector to construct a simulated satellite navigation controlled wireless field that meets the requirements.

2. A satellite navigation controlled wireless field simulation method according to claim 1, characterized in that: The hardware environment of the satellite navigation controlled wireless field includes a satellite navigation simulation source, a channel simulation subsystem, a transmitting antenna array subsystem, and a controlled wireless field microwave darkroom.

3. A satellite navigation controlled wireless field simulation method according to claim 2, characterized in that: If the transmitting antenna array of the satellite navigation controlled wireless field meets the far-field condition constraints, the central test area field amplitude uniformity condition constraints, the amplitude difference constraint between the center and the edge, and the phase difference constraint between the center and the edge, the channel simulation subsystem is simplified to form a satellite navigation signal simulator in which each channel simulates a satellite, and the broadcast satellite navigation signal no longer undergoes spatial field synthesis. The cross-regional movement of the satellite is simulated by combining the simulated source satellite motion simulation with the spatial division and airspace switching of antennas corresponding to different simulated source channels. The spatial direction change of the satellite due to orbital motion is simulated by switching from one adjacent antenna to another, thereby achieving continuous and seamless changes in the satellite motion trajectory and simulating the satellite navigation controlled wireless field.

4. A satellite navigation controlled wireless field simulation method according to claim 3, characterized in that: The far-field condition constraints are: ， in, is the distance between a single transmitting antenna and the receiving antenna under test in the microwave darkroom, is the transmitting antenna aperture, Receiving antenna aperture, is the working wavelength; The field amplitude uniformity condition constraint of the central test area is: ， in, The level amplitude changes in the central test area; The amplitude difference constraint between the center and the edge is: ， in, is the amplitude difference between the center and the edge, is the center difference between the transmitting antenna and the receiving antenna; The phase difference between the center and the edge is constrained as follows: ， in, is the array antenna element factor, is the phase difference value.

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