Communication and perception joint optimization method based on space-time coding metasurface

Abstract

The invention provides a communication and perception joint optimization method based on a space-time coding metasurface. The method comprises the following steps: step 1, modulating and sending symbols by adopting a quadrature amplitude modulation scheme; 2, performing real-time regulation and control on the programmable metasurface; step 3, the integrated multi-antenna receiver separates received signals with different frequencies by using orthogonality between harmonic waves, wherein different harmonic waves respectively correspond to a communication signal and a target echo signal; step 4, constructing a joint optimization problem model of communication and perception performance indexes; and 5, designing an improved algorithm based on a non-dominated sorting genetic algorithm to jointly optimize the communication SNR and the sensing CRB so as to improve the communication performance by using sensing assistance. According to the invention, the communication information demodulated by the zero-order harmonic can be utilized to realize the sensing of the other-order harmonic, and the sensing information of the other-order harmonic can be utilized to enhance the communication performance.

Description

Technical Field

[0001] The present invention belongs to the field of wireless communications, and in particular relates to a communication and perception joint optimization method based on space-time coding hypersurface. Background Art

[0002] With the increasing scarcity of microwave band spectrum resources, the terahertz (THz) band has become an indispensable key frequency band for the sixth generation wireless communication system (6G) due to its huge bandwidth, low latency, high-speed data transmission capability and excellent reliability. At the same time, it provides great potential and broad application prospects for the development of integrated sensing and communication (ISAC) technology. In the THz-ISAC system based on space division multiplexing, it is crucial to form multiple spatial beams, which can serve communication and sensing functions respectively. THz signals are usually combined with large-scale antenna arrays to construct multiple spatial beams through array coding technology. However, due to the limitation of the number of RF chains and the difficulty of achieving complete orthogonality between beams, interference may occur between communication signals and sensing signals. In order to ensure the orthogonality between the two, combining OFDM signals with advanced digital or hybrid beamforming technology can perform precise beamforming on different frequency bands. However, it is worth noting that OFDM signals have a high peak-to-average power ratio (PAPR), which places higher requirements on the power amplifier efficiency and the average output power of the transmitter in the THz band.

[0003] In order to address the challenge of the difficulty in fully orthogonalizing beams in ISAC systems at high frequencies, current studies have proposed the use of STC-IRS. This method generates orthogonal harmonic beams in different directions by periodically changing the spatial coding matrix, thereby supporting multi-user communications. However, research in the field of THz-ISAC is still in its early stages, so it is extremely important to design a STC-IRS-assisted THz-ISAC system and simultaneously optimize communication and perception performance. Summary of the invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to provide a communication and perception joint optimization method based on a space-time coding metasurface in view of the deficiencies of the prior art, including: establishing a Terahertz Integrated Sensing and Communication (THz-ISAC) system, including a base station, a space-time coding metasurface STC-IRS (Space-time coding-Intelligent reflecting surface, STC-IRS), K targets and an integrated multi-antenna receiver; wherein the direct path between the base station and the integrated multi-antenna receiver is blocked by obstacles, and the STC-IRS is used to assist the communication between the base station and the integrated multi-antenna receiver, and the STC-IRS includes M rows and N columns of programmable units, each unit is connected to a PIN (positive-intrinsic-negative) diode, and all coding elements can be independently controlled by a field programmable gate array (Field Programmable Gate Array, FPGA); the integrated dual-function receiver can simultaneously process communication reception signals and target echo signals, and adopts a hybrid beam reception scheme; in order to reduce hardware costs and resource waste, a hybrid beam reception scheme is adopted, and then the following steps are performed:

[0005] Step 1: In a symbol period T s In the signal, the quadrature amplitude modulation (QAM) scheme is used to modulate and transmit symbols.

[0006] Step 2, by applying different control voltages on the FPGA to the PIN diode, the reflection phase of the programmable element can be switched periodically and timely within the period T0 of the STC-IRS. By changing the coding sequence stored in the FPGA, the programmable metasurface can be controlled in real time to achieve different functions. The transmitted signal behind the reflecting surface is

[0007] Step 3: Receive signal Depend on OK The array of phase shifters is connected to receive A radio frequency (RF) chain; the integrated multi-antenna receiver uses the orthogonality between harmonics to separate received signals of different frequencies, wherein different harmonics correspond to communication signals and target echo signals respectively;

[0008] Step 4: construct a joint optimization problem model of communication and perception performance indicators;

[0009] Step 5: Design an improved algorithm based on non-dominated sorted genetic algorithm III (NSGA-III) to jointly optimize communication SNR and perception CRB, thereby using perception assistance to improve communication performance.

[0010] In step 1, the communication signal is used to detect the target at the same time. At time t, the base station sends the symbol in represents the real part, j is the imaginary unit, N b is the number of symbols, e is a natural constant, f c is the carrier frequency in the THz band, is the baseband signal in the nth symbol period, is the nth quadrature amplitude modulation QAM symbol, g(t-nT pulse ) is the period T pulse Rectangular pulse, T pulse =T l +T s , T l To expand time.

[0011] In step 2, the reflection coefficient of the time modulation of the element in the pth row and qth column is Among them U pq (t-lτ) is the periodic pulse signal within T0, τ=T0 / L is the pulse width, L represents the coding length of the time modulation sequence, represents the reflection coefficient of the element in the pth row and qth column in the lth time period. The amplitude and phase of the reflection coefficient are and Transmitted signal after reflection from the space-time coding metasurface STC-IRS Expressed as Where ω represents the harmonic order, f0 is the frequency difference between harmonics of different orders, N t ×1-dimensional vector of STC-IRS Fourier series coefficients, [·] T represents the matrix transpose, is Γ pq (t) Fourier series expansion coefficients, where p∈[1,M], q∈[1,N].

[0012] In step 3, the receiver receives the signal It contains communication signals and target echo signals, where k = 0 is the communication receiving signal, is the normalization parameter, N t=M×N is the number of transmitting antennas, is the number of antennas at the receiving end, α k is the attenuation coefficient, υ(t) is complex Gaussian white noise, and its power spectrum density is n0. is the array manifold matrix, and They represent the departure angle (AoD) and arrival angle (AoA) of the kth target, respectively. represents the transmitting array steering vector, is the transmitting end elevation angle, is the transmitting end azimuth, is the location of the STC-IRS, where are the coordinate values ​​of STC-IRS on the x, y, and z axes respectively, is the location of the integrated multi-antenna receiver, where are the coordinate values ​​of the receiver on the x, y, and z axes respectively, d0 is the distance between two elements in the plane formed by the x-axis and the y-axis, represents the receiving array steering vector, is the elevation angle of the receiving end, The integrated receiver adopts a hybrid beamforming (HBF) architecture, in which each RF chain is connected only to antennas, the structure simulates the precoder W RF belongs to a block matrix, where each submatrix is ​​a dimensional constant modulus vector, It is expressed as:

[0013]

[0014] in, Representative The phase vector corresponding to the sub-array connected by the RF chain.

[0015] In step 3, for each sub-matrix, define The optimization problem model is expressed as:

[0016]

[0017]

[0018]

[0019] η≥0

[0020] Where min(·) means minimizing the objective function, (·) l,lrepresents the l,lth element of the matrix, η is the scattering coefficient, Indicates that the angle domain Divided into I uniform grids, θ i is the depression angle, φ i is the direction angle, represents the gridded receiving array steering vector, P d (θ i ,φ i ) is the angle (θ i ,φ i ) on the ideal waveform gain;

[0021] The signal processed by the analog precoder is expressed as in(·) H represents the conjugate transpose of the matrix, and the received signal corresponding to the nth symbol on the ωth harmonic V n is the amplitude of the nth symbol, is the phase of the nth symbol; represents a mean of zero and a variance of Gaussian white noise, d is the integral symbol; is the channel matrix, τ k Represents the path delay of the signal from the kth target to the receiver, and the attenuation coefficient ε(f c ) is the atmospheric attenuation coefficient, R(f c )=γ TE (f)ρ(f) is the rough surface reflection coefficient, γ TE (f) is the smooth surface reflection coefficient obtained by the Fresnel equation, and ρ(f) is the Rayleigh roughness factor. k1 is the distance between STC-IRS and the kth target, d k2 is the distance between the kth target and the receiver.

[0022] In step 4, the joint optimization problem model of the communication and perception performance indicators is expressed as:

[0023]

[0024] in, is the signal-to-noise ratio correlation function at the receiving end, which is used to represent the communication performance index. is the phase of the nth symbol in the pth row and qth column of STC-IRS, ε avg represents the average energy of the symbol, ω0 is the digital beamforming vector at the receiving end, For the synthetic channel, f CRB (Φ) is the Cramer-Rao bound correlation function used to represent the perceptual performance index, and

[0025] are the coordinate values ​​of the kth target on the x, y, and z axes respectively. The CRB of the kth target estimation parameters, is the true weighted CRB value of the kth target, Indicates that N b There are N symbols e The probability of a symbol error.

[0026] In step 4, the probability The calculation formula is:

[0027]

[0028] In step 5, the improved algorithm based on the non-dominated sorting genetic algorithm comprises the following steps:

[0029] Step 5-1, create a parent population P t , the population size is N p , and predefine the reference point Z s ; in M p =K+1 objective function, considering p partitions, the total number of reference points is given by Given; for a 1-bit coded hypersurface, each element in the initial population is randomly generated in the range [0,2);

[0030] Step 5-2: During the optimization process, each element is considered as a variable that varies within [0,2). However, when calculating the value of the objective function, the continuous variable is discretized into the corresponding 01 code, that is, the intervals [0,0.5) and [1.5,2) are mapped to 0° phase, and [0.5,1.5) is mapped to 180°.

[0031] Step 5-3, create the tth generation offspring population Q through recombination and mutation t , and then merge the parent and offspring populations into set R t , R t =P t ∪Q t ; According to different non-dominated levels, R t Sort; construct a new population S through non-dominated levels t , non-dominated levels from F1 to F l ; if |S t |>N p , members from 1 to l-1 fronts have been selected, and the remaining population members are from the last frontier F l Select from;

[0032] Step 5-4: Normalize the target and create a reference set Z r , and then the new population S t Each member of F is associated with a reference point and is derived from l The remaining members are selected once and the offspring population P is constructed by the niche method. t+1 , and then generate a new initial population P t to replace the old population.

[0033] The present invention also provides an electronic device, comprising a processor and a memory, wherein the memory stores program code, and when the program code is executed by the processor, the processor executes the steps of the described method.

[0034] The present invention also provides a storage medium storing a computer program or instruction. When the computer program or instruction is run on a computer, the steps of the method described are executed.

[0035] The present invention provides a joint optimization scheme for communication and perception of a THz-ISAC system assisted by a space-time coding-intelligent reflecting surface (STC-IRS). The STC intelligent reflecting surface is integrated into the THz-ISAC system, the transmit beam is modulated in both the space and frequency domains, different harmonic beams are used for communication and perception respectively, and a hybrid beamforming architecture is used at the receiving end to effectively separate the communication and perception signals. The present invention constructs a multi-objective optimization framework for communication and perception performance, and uses a non-donimated sorting genetic algorithm III (NSGA-III) to jointly optimize the symbol error probability (SEP) and the Cramer-Rao Bound (CRB).

[0036] Beneficial effects: The present invention provides a communication and perception joint optimization scheme for a terahertz synaesthesia integrated system assisted by a space-time coding metasurface, which uses STC-IRS to modulate the transmit beam in both the space and frequency domains, uses different harmonic beams for communication and perception respectively, and uses a hybrid beamforming architecture at the receiving end to effectively separate communication and perception signals, and provides a communication perception performance joint optimization algorithm based on NSGA-III. The present invention can use the communication information demodulated by the 0th order harmonic to realize the perception of the remaining order harmonics, and can also use the perception information of the remaining order harmonics to enhance the communication performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0038] Figure 1 It is a system model diagram of the method of the present invention.

[0039] Figure 2a This is a schematic diagram of the coding scheme of this scheme.

[0040] Figure 2b , Figure 2c , Figure 2d It is the 2nd to 2nd order harmonic lobe diagram.

[0041] Figure 2e , Figure 2f , Figure 2g It is the -2 to 2nd order harmonic lobe diagram corresponding to the optimal solution of the binary particle swarm optimization algorithm after 1000 iterations. DETAILED DESCRIPTION

[0042] This embodiment provides a communication and perception joint optimization method based on spatiotemporal coding metasurface. Figure 1 As shown (where FPGA stands for Field Programmable Gate Array, and HBF stands for hybrid beamforming), in an embodiment of the present invention, a THz-ISAC system is first designed, including a base station, an STC-IRS, K targets, and an integrated multi-antenna receiver. Among them, the direct path between the base station and the integrated multi-antenna receiver is blocked by obstacles, and the STC-IRS is used to assist the communication between the base station and the receiver. It consists of M rows and N columns of programmable units. Since the base station and the IRS are very close, the direct path channel between the base station and the IRS is ignored. The integrated dual-function receiver can process the communication reception signal and the target echo signal at the same time. In order to reduce hardware costs and waste of resources, a hybrid beam reception scheme is adopted.

[0043] The system signal model is given below, and the transmitted symbol is:

[0044]

[0045] in represents the real part, j is the imaginary unit, N b is the number of symbols, e is a natural constant, f c is the carrier frequency in the THz band, is the baseband signal in the nth symbol period, is the nth quadrature amplitude modulation QAM symbol, g(t-nT pulse ) is the period Tpulse Rectangular pulse, T pulse =T l +T s , T l To expand time.

[0046] The transmitted symbol is reflected by the STC-IRS, and the reflection coefficient of the element time modulation in the pth row and qth column is:

[0047]

[0048] Among them U pq (t) is the periodic pulse signal within the modulation period T0, τ = T0 / L is the pulse width, L represents the coding length of the time modulation sequence, It represents the reflection coefficient of the element in the pth row and qth column in the lth time period, and its amplitude and phase are and Transmitted signal after being reflected by STC-IRS It is expressed as:

[0049]

[0050] in is Γ pq (t) Fourier series expansion coefficient. The signal received by the integrated multi-antenna receiver is:

[0051]

[0052] When k=0, it is the communication receiving signal. is the normalization parameter, N t =M×N, α k is the attenuation coefficient, υ(t) is complex Gaussian white noise, and its power spectrum density is n0, and They represent the departure angle (AoD) and arrival angle (AoA) of the kth target, respectively. is the location of the STC-IRS, for the location of the integrated multi-antenna receiver, d0 is the distance between two elements in the plane formed by the x-axis and the y-axis. A partially connected structure is applied in the receiver of the hybrid architecture. The partially connected structure connects only antennas, the simulated precoder W in this structure RF Belongs to the block matrix, expressed as:

[0053]

[0054] in, Represents the nth r The phase vector corresponding to the sub-array connected by the RF chain. For each sub-array, the following optimization problem is constructed as follows:

[0055]

[0056]

[0057]

[0058] η≥0 (6)

[0059] Where η is the scattering coefficient, Indicates that the angle domain Divided into I uniform grids, P d (θ i ,φ i ) is the angle (θ i ,φ i ) on the ideal waveform gain, The signal after the large-scale phase shifter takes over is represented by The received signal corresponding to the nth symbol on the ωth order harmonic represents a mean of zero and a variance of Gaussian white noise, is the channel matrix, the attenuation coefficient ε(f c ) is the atmospheric attenuation coefficient, R(f c )=γ TE (f)ρ(f) is the rough surface reflection coefficient, γ TE (f) is the smooth surface reflection coefficient obtained by the Fresnel equation, and ρ(f) is the Rayleigh roughness factor. k1 is the distance between STC-IRS and the kth target, d k2 is the distance between the kth target and the receiver. The joint optimization problem of communication and perception performance indicators can be expressed as:

[0060]

[0061]

[0062] where ε avg represents the average energy of the symbol, ω0 is the digital beamforming vector at the receiving end, f CRB (Φ)=[f k CRB (Φ)], k = 1, ..., K, and:

[0063]

[0064] in, Indicates that N b There are N symbols e The probability of a symbol error.

[0065] Problem P1 expresses a multi-objective optimization problem, where the objective function f should be minimized. If a specific objective function needs to be maximized, its negative value can be minimized by redefining the problem. Therefore, formula (8) represents the maximum value of the signal-to-noise ratio. Formula (9) represents the optimal detection performance achieved in the i-th spatial domain. Multi-objective optimization problems (multi-OOPs) use Pareto solution sets to represent their optimality. The Pareto set includes all non-inferior solutions. Multi-objective evolutionary algorithms (MOEAs) are effectively used to solve multi-objective optimization problems. When a problem involves four or more objectives, it is classified as a many-objective optimization problem (many-OOP). Compared with multi-objective optimization problems, solving many-objective optimization problems is computationally more complex, especially in terms of diversity metric evaluation, recombination operations, and performance indicator calculations. This NSGA-III algorithm includes the following steps:

[0066] 1. You need to create a parent population P t (The population size is N p ), and predefine the reference point Z s Consider p partitions on each target, then in M p The total number of reference points in the target problem is given by Given. For a 1-bit coded hypersurface, each Φ element in the initial population is randomly generated in the range [0,2).

[0067] 2. During the optimization process, each element is considered as a variable that changes within [0,2), but when calculating the value of the objective function, the continuous variable is discretized into the corresponding 01 code. That is, the intervals [0,0.5) and [1.5,2) are mapped to 0° phase, and [0.5,1.5) is mapped to 180°.

[0068] 3. Create the tth generation offspring population Q through recombination and mutation t , and then merge the parent and offspring populations into R t =P t ∪Q t According to different non-dominated levels, R t Sort. Construct a new population S through non-dominated levels t , from F1 to F l If |S t |>Np , members from 1 to l-1 fronts have been selected, and the remaining population members are from the last frontier F l Select in.

[0069] 4. Normalize the target and create a reference set Z r , then S t Each member of F is associated with a reference point and is derived from l Select the remaining members to construct P t+1 , through the Niching method. After that, a new initial population P is generated t to replace the old population.

[0070] Finally, the proposed method was simulated and verified. Assuming M=N=64, L=8, Center frequency f c =0.25THz, T0=0.05μs, T s =1μs, N b =32, atmospheric attenuation coefficient ε(f c )=0.4,M s =16, noise power spectrum density n0 = 10 -17 , harmonic frequency difference Δf=20MHz, RF link number Symbol string transmission power N b ε avg =1W.

[0071] Figure 2a , Figure 2b , Figure 2c , Figure 2d , Figure 2e , Figure 2f and Figure 2g (where L is the length of the time series, N is the number of STC-IRS columns, and θ is the azimuth angle), the scheme proposed in this embodiment is compared with the binary particle swarm algorithm. The population size of the comparison method is set to 70, the self-learning factor is 1.5, the group learning factor is 1.5, the upper and lower bounds of the speed are 5 and -5 respectively, and the inertia weight w is updated using a linear decreasing weight strategy:

[0072]

[0073] where w max =0.8, w min =0.4. Figure 2e , Figure 2f , Figure 2gThe lobe effect diagrams of the 0th order harmonic, ±1st order harmonic and ±2nd order harmonic are shown respectively. It can be seen that the maximum zero-degree gain of the 0th order harmonic is about 29dB. Compared with the multi-objective optimization solution, the main lobe of the zeroth order harmonic used for communication differs by about 6dB. The main lobes of other order harmonics used for detection are not obvious, and the difference between the main lobe and the side lobe is very small, which may lead to increased interference between multiple targets and reduced detection performance when there are multiple targets in space. The coding scheme obtained by solving the binary particle swarm algorithm is used to calculate the communication and detection performance, and the signal-to-noise ratio is 13.5dB. The CRB values ​​of the three targets are 29.92m and 29.92m, respectively. 2 ,2.01m 2 and 1.56m 2 Compared with the coding scheme obtained by solving the multi-objective optimization problem with the NSGA-III method, the communication performance and detection performance of this method are inferior.

[0074] The present invention provides a method for joint optimization of communication and perception based on spatiotemporal coding metasurface. There are many methods and ways to implement the technical solution. The above is only a preferred implementation of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A communication and perception joint optimization method based on spatiotemporal coding metasurface, characterized in that: A terahertz communication and perception integrated system is established, comprising a base station, a space-time coding metasurface STC-IRS, K targets and an integrated multi-antenna receiver; wherein the direct path between the base station and the integrated multi-antenna receiver is blocked by obstacles, and the STC-IRS is used to assist the communication between the base station and the integrated multi-antenna receiver, and the STC-IRS comprises M rows and N columns of programmable units, each of which is connected to a PIN diode, and all coding elements can be independently controlled by a field programmable gate array FPGA; the integrated dual-function receiver can simultaneously process communication reception signals and target echo signals, and adopts a hybrid beam reception scheme; and then the following steps are performed: Step 1: In a symbol period T s In the QAM scheme, the quadrature amplitude modulation (QAM) scheme is used to modulate and transmit symbols; Step 2, by applying different control voltages on the FPGA to the PIN diode, the reflection phase of the programmable element can be switched periodically and timely within the period T0 of the STC-IRS, and the programmable metasurface can be controlled in real time by changing the coding sequence stored in the FPGA; pq (t), The transmitted signal behind the reflecting surface is Step 3: Receive signal Depend on OK The array of phase shifters is connected to receive The integrated multi-antenna receiver uses the orthogonality between harmonics to separate the received signals of different frequencies, wherein different harmonics correspond to the communication signal and the target echo signal respectively; Step 4: construct a joint optimization problem model of communication and perception performance indicators; Step 5: Design an improved algorithm based on non-dominated sorting genetic algorithm to jointly optimize communication SNR and perception CRB.

2. The method according to claim 1, characterized in that In step 1, the communication signal is used to detect the target at the same time. At time t, the base station sends the symbol in represents the real part, j is the imaginary unit, N b is the number of symbols, e is a natural constant, f c is the carrier frequency in the THz band, is the baseband signal in the nth symbol period, is the nth quadrature amplitude modulation QAM symbol, g(t-nT pulse ) is the period T pulse Rectangular pulse, T pulse =T l +T s , T l To expand time.

3. The method according to claim 2, characterized in that In step 2, the reflection coefficient of the time modulation of the element in the pth row and qth column is Among them U pq (t-lτ) is the periodic pulse signal within T0, τ=T0 / L is the pulse width, L represents the coding length of the time modulation sequence, represents the reflection coefficient of the element in the pth row and qth column in the lth time period. The amplitude and phase of the reflection coefficient are and Transmitted signal after reflection from the space-time coding metasurface STC-IRS Expressed as Where ω represents the harmonic order, f0 is the frequency difference between harmonics of different orders, N t ×1-dimensional vector of STC-IRS Fourier series coefficients, [·] T represents the matrix transpose, is Γ pq (t) Fourier series expansion coefficients, where p∈[1,M], q∈[1,N].

4. The method according to claim 3, characterized in that In step 3, the receiver receives the signal It contains communication signals and target echo signals, where k = 0 is the communication receiving signal, is the normalization parameter, N t =M×N is the number of transmitting antennas, is the number of antennas at the receiving end, α k is the attenuation coefficient, υ(t) is complex Gaussian white noise, and its power spectrum density is n0. is the array manifold matrix, and denote the launch angle and arrival angle of the kth target respectively, represents the transmitting array steering vector, is the transmitting end elevation angle, is the transmitting end azimuth, is the location of the STC-IRS, where are the coordinate values ​​of STC-IRS on the x, y, and z axes respectively, is the location of the integrated multi-antenna receiver, where are the coordinate values ​​of the receiver on the x, y, and z axes respectively, d0 is the distance between two elements in the plane formed by the x-axis and the y-axis, represents the receiving array steering vector, is the elevation angle of the receiving end, is the azimuth of the receiving end; The integrated receiver uses a hybrid beamforming architecture where each RF chain connects only antennas, the structure simulates the precoder W RF belongs to a block matrix, where each submatrix is ​​a dimensional constant modulus vector, It is expressed as: in, Representative The phase vector corresponding to the sub-array connected by the RF chain.

5. The method according to claim 4, characterized in that In step 3, for each sub-matrix, define The optimization problem model is expressed as: η≥0 Where min(·) means minimizing the objective function, (·) l,l represents the l,lth element of the matrix, η is the scattering coefficient, Indicates that the angle domain Divided into I uniform grids, θ i is the depression angle, φ i is the direction angle, represents the gridded receiving array steering vector, P d (θ i ,φ i ) is the angle (θ i ,φ i ) on the ideal waveform gain; The signal processed by the analog precoder is expressed as in(·) H represents the conjugate transpose of the matrix, and the received signal corresponding to the nth symbol on the ωth harmonic V n is the amplitude of the nth symbol, is the phase of the nth symbol; represents a mean of zero and a variance of Gaussian white noise, d is the integral symbol; is the channel matrix, τ k Represents the path delay of the signal from the kth target to the receiver, and the attenuation coefficient ε(f c ) is the atmospheric attenuation coefficient, R(f c )=γ TE (f)ρ(f) is the rough surface reflection coefficient, γ TE (f) is the smooth surface reflection coefficient obtained by the Fresnel equation, ρ(f) is the Rayleigh roughness factor, d k1 is the distance between STC-IRS and the kth target, d k2 is the distance between the kth target and the receiver.

6. The method according to claim 5, characterized in that In step 4, the joint optimization problem model of the communication and perception performance indicators is expressed as: in, is the signal-to-noise ratio correlation function at the receiving end, which is used to represent the communication performance index. is the phase of the nth symbol in the pth row and qth column of STC-IRS, ε avg represents the average energy of the symbol, ω0 is the digital beamforming vector at the receiving end, For the synthetic channel, f CRB (Φ) is the Cramer-Rao bound correlation function used to represent the perceptual performance index, and are the coordinate values ​​of the kth target on the x, y, and z axes respectively. The CRB of the kth target estimation parameters, is the true weighted CRB value of the kth target, Indicates that N b There are N symbols e The probability of a symbol error.

7. The method according to claim 6, characterized in that In step 4, the probability The calculation formula is:

8. The method according to claim 7, characterized in that In step 5, the improved algorithm based on the non-dominated sorting genetic algorithm comprises the following steps: Step 5-1, create a parent population P t , the population size is N p , and predefine the reference point Z s ; in M p =K+1 objective function, considering p partitions, the total number of reference points is given by Given; for a 1-bit coded hypersurface, each element in the initial population is randomly generated in the range [0,2); Step 5-2: During the optimization process, each element is considered as a variable that varies within [0,2). However, when calculating the value of the objective function, the continuous variable is discretized into the corresponding 01 code, that is, the intervals [0,0.5) and [1.5,2) are mapped to 0° phase, and [0.5,1.5) is mapped to 180°. Step 5-3, create the tth generation offspring population Q through recombination and mutation t , and then merge the parent and offspring populations into set R t , R t =P t ∪Q t ; According to different non-dominated levels, R t Sort; construct a new population S through non-dominated levels t , non-dominated levels from F1 to F l ; if |S t |>N p , members from 1 to l-1 fronts have been selected, and the remaining population members are from the last frontier F l Select from; Step 5-4: Normalize the target and create a reference set Z r , and then the new population S t Each member of F is associated with a reference point and is derived from l The remaining members are selected once and the offspring population P is constructed by the niche method. t+1 , and then generate a new initial population P t to replace the old population.

9. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the memory stores program codes, and when the program codes are executed by the processor, the processor executes the steps of the method according to any one of claims 1 to 8.

10. A storage medium, characterized in that: A computer program or instruction is stored, and when the computer program or instruction is run on a computer, the steps of the method according to any one of claims 1 to 8 are executed.

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