SAAs-based integrated sensing and backscatter communication method

Abstract

The invention discloses an SAAs-based integrated sensing and backscatter communication method, which is applied to an SAAs-based integrated sensing and backscatter communication system. According to the invention, sensing and backscatter communication are integrated with SAAs with a high scanning rate; the receiving SAAs receives pilot signals in different modulation states by modulating the load impedance of the tag to enhance backscattering, so that a combined voltage component and an antenna voltage component are calculated, and a first reflection coefficient vector and a second reflection coefficient vector are estimated in combination with a measurement matrix; perception of the label and the clutter scatterer is realized through the first reflection coefficient vector, and label identification is realized through the second reflection coefficient vector; meanwhile, due to the high scanning rate of the SAAs, the system can realize an integrated communication function with fewer antennas and narrower working bandwidth.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to an integrated sensing and backscattering communication method based on SAAS. Background Art

[0002] Backscatter communication technology is one of the key technologies for the design of "green" Internet of Things and 6G networks, which can achieve "green" communication with low power consumption, low cost and easy deployment. In order to make better use of backscatter technology, Integrated Sensing and Communication (ISAC) has emerged. Communication systems and sensor systems use the same efficient spectrum and hardware resources to improve cost-effectiveness and enhance communication and sensing. However, traditional synthetic aperture radar (SAR) imaging systems often have problems such as slow imaging speed and high complexity due to their reliance on phased arrays, mechanical and electronic scanning mechanisms. By adopting a frequency diversity scheme, fast spatial data acquisition is achieved, thereby eliminating the need for mechanical motion or active switching components, providing a promising electronic alternative to traditional imaging.

[0003] Technologies such as frequency-variable aperture antennas, metamaterial antennas, and high-scan rate leaky-wave antennas have been used to create fast, low-cost, and low-profile microwave imaging systems with good resolution and coverage, capable of high-quality imaging in seconds. These technologies show great potential in providing high-fidelity imaging and precise localization reconstruction for clutter scatterers with time-invariant reflectivity. However, the above microwave imaging systems have not yet achieved integrated communications, and in backscatter communications, some can only detect clutter scatterers, while others can only detect tags. Summary of the invention

[0004] The present invention provides an integrated sensing and backscattering communication method based on SAAs, which is used to solve the technical problems that the existing microwave imaging system has not yet realized integrated communication and it is difficult to accurately identify tags and clutter scatterers in backscattering communication.

[0005] The present invention provides an integrated sensing and backscattering communication method based on SAAs, which is applied to an integrated sensing and backscattering communication system based on SAAs, wherein the system comprises transmitting SAAs, receiving SAAs and a sensing area, wherein the sensing area comprises a tag and a clutter scatterer, wherein the sensing area is discretized into N pixel points, and the working bandwidth of the system is divided into frequency; the method comprising:

[0006] Sending a pilot signal to the tag through the transmitting SAAs, modulating the load impedance of the tag at different frequencies so that the tag generates pilot signals in different modulation states, and backscattering the pilot signals in different modulation states to the receiving SAAs;

[0007] The receiving SAAs receive pilot signals in different modulation states to obtain corresponding receiving voltages, and the combined voltage components associated with the structural modes of the clutter scatterer and the tag and the antenna voltage components associated with the antenna mode of the tag are calculated through the different receiving voltages;

[0008] Measure the TE field measurement results of all pixels in the sensing area at different frequencies to obtain a measurement matrix;

[0009] estimating a first reflection coefficient vector and a second reflection coefficient vector based on the measurement matrix and the combined voltage components and the antenna voltage components at all frequencies;

[0010] The first reflection coefficient vector is used to sense clutter scatterers and tags, and the second reflection coefficient vector is used to identify tags from clutter scatterers.

[0011] More specifically, the step of sending a pilot signal to the tag through the transmitting SAAs, modulating the load impedance of the tag so that the tag generates pilot signals under different modulation states, and backscattering the pilot signals under different modulation states to the receiving SAAs includes:

[0012] sending a pilot signal to the tag via the transmitting SAAs;

[0013] Under the BPSK modulation mode, the load impedance of the tag at different frequencies is modulated respectively so that the tag generates a pilot signal in an open circuit state and a pilot signal in a short circuit state;

[0014] The pilot signal in the open circuit state and the pilot signal in the short circuit state are backscattered by the tag to the receiving SAAs.

[0015] More specifically, the sensing area includes a tag and a clutter scatterer; the receiving SAAs receives pilot signals in different modulation states to obtain corresponding receiving voltages, and the steps of respectively calculating the combined voltage components associated with the structural modes of the clutter scatterer and the tag and the antenna voltage components associated with the antenna mode of the tag through the different receiving voltages include:

[0016] The receiving SAAs receive pilot signals in different modulation states to obtain a receiving voltage of the pilot signal corresponding to an open circuit state and a receiving voltage of the pilot signal corresponding to a short circuit state;

[0017] Calculate the average value of the sum of the received voltage of the pilot signal corresponding to the open circuit state and the received voltage of the pilot signal corresponding to the short circuit state to obtain a combined voltage component associated with the structural mode of the clutter scatterer and the tag;

[0018] The average value of the difference between the received voltage of the pilot signal corresponding to the open circuit state and the received voltage of the pilot signal corresponding to the short circuit state is calculated to obtain the antenna voltage component associated with the antenna mode of the tag.

[0019] More specifically, the first reflection coefficient vector and the second reflection coefficient vector are estimated based on the measurement matrix and the combined voltage components and antenna voltage components at all frequencies;

[0020] Based on the combined voltage components and the antenna voltage components at all frequencies, a combined voltage component vector and an antenna voltage vector are constructed respectively;

[0021] Establishing a linear relationship between the measurement matrix and the combined voltage component vector, and estimating a first reflection coefficient vector using a compressed sensing and two-step iterative shrinkage algorithm;

[0022] A linear relationship between the measurement matrix and the antenna voltage component is established, and a second reflection coefficient vector is estimated by using compressed sensing and a two-step iterative shrinkage algorithm.

[0023] More specifically, the received voltage is expressed as follows:

[0024]

[0025] Where: Indicates the frequency The receiving voltage under Indicates the frequency The combined voltage components associated with the structural modes of the clutter scatterers and the tag are shown below; Represents the reflection coefficient associated with the load impedance of the tag, Γ=1 means the tag is in an open circuit state, Γ=-1 means the tag is in a short circuit state; Indicates the frequency The antenna voltage component associated with the tag's antenna pattern;

[0026] Then, under BPSK modulation, the combined voltage component associated with the structural mode of the clutter scatterer and the tag is It is expressed as:

[0027]

[0028] Where: Indicates the frequency The following is the received voltage of the pilot signal corresponding to the open circuit state, Indicates the frequency The receiving voltage of the pilot signal corresponding to the short-circuit state;

[0029] Among them, the antenna voltage component associated with the tag's antenna mode is It is expressed as:

[0030] .

[0031] More specifically,

[0032] The process of establishing the linear relationship between the measurement matrix and the combined voltage component vector is expressed as follows:

[0033]

[0034] Where: represents the combined voltage component vector, where ; represents the measurement matrix; represents the first reflection coefficient vector, where ;

[0035] The process of estimating the first reflection coefficient vector using compressed sensing and a two-step iterative shrinkage algorithm is expressed as follows:

[0036]

[0037] Where: ||·||1 is the l1 norm;

[0038] The process of establishing the linear relationship between the measurement matrix and the antenna voltage component is expressed as follows:

[0039]

[0040] Where: represents the antenna voltage vector, where ; represents the second reflection coefficient vector, where ;

[0041] The process of estimating the second reflection coefficient vector using compressed sensing and a two-step iterative shrinkage algorithm is expressed as follows:

[0042] .

[0043] More specifically, the transmitting SAAs and the receiving SAAs both adopt a single-plane coupled waveguide cavity design and are mounted on a 0.508 mm Rogers RT 5880 substrate.

[0044] More specifically, the sizes of the transmitting SAAs and the receiving SAAs are both 186×165 mm; the spacing distance between the transmitting SAAs and the receiving SAAs on the x-axis is 40 mm.

[0045] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of any of the above-mentioned SAAs-based integrated sensing and backscatter communication methods.

[0046] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the steps of any of the above-mentioned integrated sensing and backscattering communication methods based on SAAs are implemented.

[0047] It can be seen from the above technical solutions that the present invention has the following advantages:

[0048] The invention provides an integrated sensing and backscattering communication method based on SAAs, which is applied to an integrated sensing and backscattering communication system based on SAAs. The system comprises transmitting SAAs, receiving SAAs and a sensing area, and the sensing area comprises a tag and a clutter scatterer. The method comprises: sending a pilot signal to the tag through the transmitting SAAs, modulating the load impedance of the tag at different frequencies so that the tag generates a pilot signal under different modulation states, and backscattering the pilot signal under different modulation states to the receiving SAAs; receiving the pilot signal under different modulation states by the receiving SAAs to obtain a corresponding receiving voltage, and respectively calculating a combined voltage component associated with a structural mode of the clutter scatterer and the tag and an antenna voltage component associated with an antenna mode of the tag through different receiving voltages; measuring TE field measurement results of all pixel points in the sensing area at different frequencies to obtain a measurement matrix; respectively estimating a first reflection coefficient vector and a second reflection coefficient vector based on the measurement matrix and the combined voltage component and the antenna voltage component at all frequencies; using the first reflection coefficient vector to sense the clutter scatterer and the tag, and using the second reflection coefficient vector to identify the tag from the clutter scatterer.

[0049] In the present invention, sensing and backscattering communication are integrated with SAAs with a high scanning rate; the load impedance of the tag is modulated so that the receiving SAAs receive pilot signals in different modulation states to enhance backscattering, thereby calculating the combined voltage component and the antenna voltage component, and combining with the measurement matrix, estimating the first reflection coefficient vector and the second reflection coefficient vector, realizing the perception of the tag and the clutter scatterer through the first reflection coefficient vector, and realizing the tag identification through the second reflection vector; at the same time, due to the high scanning rate of SAAs, the system can realize the integrated communication function with fewer antennas and narrower working bandwidth, thereby solving the technical problems that the existing microwave imaging system has not yet realized integrated communication and it is difficult to accurately identify the tag and the clutter scatterer in the backscattering communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0051] Figure 1 A flowchart of a method for integrated sensing and backscattering communication based on SAAs provided in an embodiment of the present invention;

[0052] Figure 2 A model diagram of an integrated sensing and backscattering communication system based on SAAs provided in an embodiment of the present invention;

[0053] Figure 3 An effect diagram of the independent measurement capability of the system provided by an embodiment of the present invention within the working bandwidth;

[0054] Figure 4 An effect diagram of the perception and recognition results of a single tag and a clutter scatterer provided by an embodiment of the present invention;

[0055] Figure 5 An effect diagram of the perception and recognition results of multiple tags and a single clutter scatterer provided by an embodiment of the present invention;

[0056] Figure 6 The effect diagram of the BPSK signal bit error rate performance under different signal-to-noise ratios of the system provided by the embodiment of the present invention. DETAILED DESCRIPTION

[0057] The embodiment of the present invention provides an integrated sensing and backscattering communication method based on SAAs, which is used to solve the technical problems that the existing microwave imaging system has not yet achieved integrated communication and it is difficult to accurately identify tags and clutter scatterers in backscattering communication.

[0058] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] See also Figure 1 The first aspect of the present invention provides an integrated sensing and backscattering communication method based on SAAs, comprising:

[0060] Step 101, sending a pilot signal to a tag by transmitting SAAs, modulating the load impedance of the tag at different frequencies so that the tag generates pilot signals under different modulation states, and backscatters the pilot signals under different modulation states to receiving SAAs.

[0061] It should be noted that the present invention is applied to an integrated sensing and backscattering communication system based on SAAs, which integrates sensing and backscattering communication functions; the transceiver of the system is composed of a pair of high scanning-rate frequency-diverse slot array antennas (SAAs) to ensure reliable backscattering communication; at the same time, due to the high scanning rate of SAAs, the system can realize integrated communication functions with fewer antennas and a narrower working bandwidth.

[0062] For details, please refer to Figure 2 The system includes transmitting SAAs, receiving SAAs and sensing area. The transmitting SAAs and receiving SAAs are spaced apart along the x-axis direction. The spacing is d. The sensing area refers to the spatial range in which the system can perceive and detect. Figure 2 The medium sensing region may be defined as a one-dimensional (1D) line region along the x-axis located in the antenna near-field region.

[0063] The sensing area contains clutter scatterers with fixed reflection coefficients and tags that can change their reflectivity for backscatter communication. The sensing area is discretized into N uniform pixels with an interval of These pixels are indexed by n, where n∈{1,2,...,N}; the system's operating bandwidth is divided into N f frequency.

[0064] The main goal of the present invention is to accurately detect and distinguish these dynamic tags in a cluttered environment. The present invention combines sparsity and inverse scattering techniques to enhance tag detection and identification, while using maximum ratio combining (MRC) technology to extract antenna patterns to obtain channel state information (CSI), thereby enhancing backscatter communication.

[0065] This step specifically includes:

[0066] Sub-step 1011, sending a pilot signal to the tag by transmitting SAAs.

[0067] Sub-step 1012, in the BPSK modulation mode, modulate the load impedance of the tag at different frequencies respectively so that the tag generates a pilot signal in an open circuit state and a pilot signal in a short circuit state.

[0068] It should be noted that at a given frequency Under the Born approximation (BA), the pilot signal / received signal received by the receiving SAAs can be expressed as voltage express:

[0069]

[0070] Where: j = represents the imaginary unit, ω represents the angular frequency, is the free space permeability, represents the normalization constant, represents the position vector, represents the reflection coefficient; Represents the transmitting SAAs and receiving SAAs at The incident electric field at .

[0071] For simplicity, this embodiment considers a sensing area including a tag and a clutter scatterer. Then, the received signal in equation (1) can be composed of two parts:

[0072] Part of it comes from the tag's structural mode and clutter scatterers, and the other part comes only from the tag's antenna mode. Among them, the tag's structural mode is not affected by changes in the tag's load state, which is determined by the physical characteristics of the object in the sensing area, such as shape, size, position and material composition. In contrast, the tag's antenna mode will change with the tag's load impedance Z. L changes with the changes of.

[0073] The load impedance of the tag is Z L The change of is reflected by the reflection coefficient Γ, as shown in formula (2):

[0074]

[0075] Where: represents the complex conjugate operation, Z A is the antenna impedance of the SAAs, Indicates the load impedance of the tag.

[0076] It can be seen that by changing the load impedance Z L , the tag can present different reflection coefficients through the antenna mode. In order to simplify and verify the integrated sensing and backscattering communication system, the present invention adopts the binary phase shift keying (BPSK) modulation scheme as the modulation method, which is represented by the load impedance in the open circuit state and the short circuit state. When Z L =∞, Γ=1 in the open circuit state; when Z L =0, Γ=-1 in the short-circuit state.

[0077] For example, when the tag is in an open circuit state, the load impedance tends to infinity and the reflection coefficient is close to 1. In this case, the tag hardly absorbs the incident wave and most of the energy is reflected back to the source antenna (transmitting SAAs). Therefore, the antenna pattern of the tag exhibits a highly reflective state.

[0078] Sub-step 1013, backscattering the pilot signal in the open circuit state and the pilot signal in the short circuit state to the receiving SAAs through the tag.

[0079] It should be noted that the present invention uses inverse scattering technology to extract information about tags and clutter scatterers from the signals received by receiving SAAs. By adjusting the load impedance of the tag, signals in different states can be collected, which can be used to reconstruct the position and characteristics of the tag and clutter scatterers.

[0080] Step 102, receiving pilot signals in different modulation states by receiving SAAs to obtain corresponding receiving voltages, and calculating the combined voltage components associated with the structural modes of the clutter scatterer and the tag and the antenna voltage components associated with the antenna mode of the tag through the different receiving voltages.

[0081] This step specifically includes:

[0082] In sub-step 1021, receiving SAAs receives pilot signals in different modulation states to obtain a receiving voltage of the pilot signal corresponding to an open circuit state and a receiving voltage of the pilot signal corresponding to a short circuit state.

[0083] It should be noted that when the sensing area contains a tag and a clutter scatterer, equation (1) can be expressed as the combined voltage component / constant component generated by the tag's structural mode and the clutter scatterer (Wherein, the reflection coefficient is expressed as ) and a variable component associated with the tag antenna pattern (Wherein, the reflection coefficient is expressed as ) combination.

[0084] therefore, can be written as:

[0085]

[0086] Where: Represents the reflection coefficient associated with the load impedance of the tag, Γ=1 means the tag is in an open circuit state, Γ=-1 means the tag is in a short circuit state; Indicates the frequency The antenna voltage component associated with the tag's antenna pattern.

[0087] Similarly, in the position vector The reflection coefficient shown below It can be expressed as:

[0088]

[0089] In the present invention, it is possible to use To sense clutter scatterers and tags, use To identify tags from clutter scatterers. and In order to perform accurate sensing and identification, the load impedance of the tag is modulated to be in an open circuit state and a short circuit state under the BPSK modulation mode, and the receiving voltage of different modulation states at different frequencies is recorded by the receiving SAAs:

[0090] The tag utilizes a reflectivity and The two pilot signals are used for backscatter communication. According to equation (3), the corresponding received voltages of the two pilot signals are given by the following equation:

[0091] exist The received voltage of the pilot signal corresponding to the open circuit state obtained by receiving SAAs at the frequency It is expressed as follows:

[0092]

[0093] exist The received voltage of the pilot signal corresponding to the short-circuit state obtained by receiving SAAs at the frequency It is expressed as follows:

[0094]

[0095] Sub-step 1022, calculating the average of the sum of the received voltage of the pilot signal corresponding to the open circuit state and the received voltage of the pilot signal corresponding to the short circuit state, and obtaining a combined voltage component associated with the structural mode of the clutter scatterer and the tag.

[0096] Then, at the frequency The combined voltage components associated with the clutter scatterers and the tag's structural modes It is expressed as:

[0097]

[0098] Sub-step 1023, calculating the average value of the difference between the received voltage of the pilot signal corresponding to the open circuit state and the received voltage of the pilot signal corresponding to the short circuit state, and obtaining the antenna voltage component associated with the antenna mode of the tag.

[0099] Then, at the frequency The antenna voltage component associated with the tag's antenna pattern It is expressed as:

[0100]

[0101] Step 103, measuring the TE field measurement results of all pixel points in the sensing area at different frequencies to obtain a measurement matrix.

[0102] It should be noted that for N f frequency measurements and N pixels, the measurement matrix In the measurement matrix H, each row corresponds to a specific frequency sample, and each column corresponds to a specific pixel point, so the nth f The row and column n element H nf,n Indicates that in the nth f The electromagnetic field (TE field) measurement results in the transverse electromagnetic wave mode at the nth pixel point at a frequency are:

[0103]

[0104] It can be understood that the measurement matrix H collects information about the electromagnetic field distribution in the sensing area, which has information diversity, so that the subsequent steps can recover sparse signals from the linear relationship combination.

[0105] Step 104: Estimate a first reflection coefficient vector and a second reflection coefficient vector based on the measurement matrix and the combined voltage components and antenna voltage components at all frequencies.

[0106] This step specifically includes:

[0107] Sub-step 1041 , based on the combined voltage components and the antenna voltage components at all frequencies, respectively construct a combined voltage component vector and an antenna voltage vector.

[0108] It is understandable that for N f frequency measurements, constructing the combined voltage vector and the antenna voltage vector represent the received voltage of the tag structure mode and clutter scatterer and the received voltage of the tag antenna mode respectively.

[0109] It should be noted that the present invention uses maximum ratio combining (MRC) technology to process and combine signals from different frequencies received by SAAs to improve the reliability and performance of backscatter communication. After combining the signals using MRC technology, the combined voltage vector and the antenna voltage vector , and the antenna voltage vector The change of directly reflects the change of the tag's load impedance, which carries information about the channel state information (CSI). These signal data are then used to estimate the response state of the channel, including characteristics such as signal amplitude, phase, and polarization.

[0110] Sub-step 1042, establishing a linear relationship between the measurement matrix and the combined voltage component vector, and using compressed sensing and a two-step iterative shrinkage algorithm to estimate the first reflection coefficient vector.

[0111] In this scheme, the relative strength of the received signal is mainly represented by the reflection coefficient, so the reflection coefficient contains key information about the target location and characteristics. Based on formula (1), the amplitude coefficient can be ignored (compared with the reflection coefficient, the amplitude coefficient is weaker in the received signal, where the amplitude coefficient includes parameters such as angular frequency and free space permeability). Then the process of establishing the linear relationship between the measurement matrix and the combined voltage component vector is expressed as follows:

[0112]

[0113] Where: represents the first reflection coefficient vector, ; In formula (10), the distribution of the reflection coefficient in the first reflection coefficient vector is determined by measuring the matrix.

[0114] Using compressed sensing and a two-step iterative shrinkage / thresholding algorithm, formula (10) can be solved as:

[0115]

[0116] This allows the estimation of the first reflection coefficient vector, but only using Only clutter scatterers and tags can be sensed, which is not enough to identify tags from clutter scatterers. In order to further identify tags from clutter scatterers, it is necessary to use To identify the label, we can use the above formulas (10) and (11) and and and By swapping them one by one, we can estimate , as shown in sub-step 1043.

[0117] Sub-step 1043, establishing a linear relationship between the measurement matrix and the antenna voltage component, and using compressed sensing and a two-step iterative shrinkage algorithm to estimate the second reflection coefficient vector.

[0118] The process of establishing a linear relationship between the measurement matrix and the antenna voltage components is expressed as follows:

[0119]

[0120] Where: represents the second reflection coefficient vector, where ;

[0121] The process of estimating the second reflection coefficient vector using compressed sensing and a two-step iterative shrinkage algorithm is expressed as follows:

[0122]

[0123] It is understandable that, generally, there are only a few significant reflection coefficients in the sensing area. The present invention uses compressed sensing and a two-step iterative shrinkage / threshold algorithm to recover sparse signals from limited measurement data, thereby achieving accurate recovery of the signal.

[0124] Step 105: Use the first reflection coefficient vector to sense the clutter scatterer and the tag, and use the second reflection coefficient vector to identify the tag from the clutter scatterer.

[0125] In this embodiment, the SAAs adopts a single-plane coupled waveguide cavity design. The SAAs is mounted on a 0.508 mm RogersRT 5880 substrate, operates in the 3.975-4.025 GHz range, and has a size of 186×165 mm. It achieves a return loss of less than -10 dB and maintains a radiation efficiency of 82%. In addition, the SAAs is able to scan from 60 degrees to 130 degrees over a 50 MHz bandwidth.

[0126] It can be understood that compared with traditional synthetic aperture radar imaging systems, because the present invention does not rely on phased arrays, mechanical and electronic scanning mechanisms, the imaging speed is faster and the complexity is greatly reduced; compared with existing MIMO solutions that include communication functions, the number of antennas required by this system is significantly reduced; at the same time, compared with traditional mechanical or electronic beam steering methods, this system has the characteristics of low profile and low cost, and can achieve real-time sensing within a narrow bandwidth.

[0127] The present invention integrates sensing and backscatter communications with SAAs with a high scanning rate. Compared with existing technologies such as variable frequency aperture antennas, metamaterial antennas and high scanning rate leaky wave antennas, the present invention utilizes the high scanning rate based on SAAs to quickly and accurately realize simultaneous detection and identification of tags and clutter scatterers, while realizing integrated communication. The system uses fewer antennas and occupies a narrower bandwidth.

[0128] As an example, a frequency-divided integrated sensing and backscatter communication system with a diameter of d = 40 mm was constructed using two SAAs. The sensing area spanned 430 mm along the x-axis and was 50 mm from the SAAs along the z-axis. The area was divided into N = 431 pixels with an interval of Δl = 1 mm. The frequency range from 3.975 to 4.025 GHz was sampled at 0.001 GHz intervals, resulting in N f = 51 frequency samples; the measurement matrix H is collected by measuring the TE field at 431 pixel locations at 51 frequencies.

[0129] Combined with the examples, the present invention also provides simulation results based on comprehensive three-dimensional electromagnetic simulation, demonstrating the sensing, recognition and communication functions of the present solution, please refer to Figure 3-Figure 6 .

[0130] Singular value decomposition (SVD) and perceived capacity techniques are often used to evaluate the pattern diversity capability of a proposed antenna; see Figure 3 , Figure 3 Demonstrated the ability to perform independent measurements of the antenna within the operating bandwidth, where Figure 3 (a) shows the system's singular value (normalized) spectral distribution, and Figure 3(b) demonstrates the system's sensing capability, indicating that the system can achieve synchronous backscattering communication in a cluttered environment within a 50 MHz operating bandwidth.

[0131] The sensing area includes a tag and a copper clutter scatterer of equal size as the test object, where the tag is a copper dipole antenna with a radius of 10mm and a height of 31.5mm; see Figure 4 , Figure 4 The results of sensing and identifying single tags and clutter scatterers are shown. Figure 4 In the figure, the blue line is the reconstructed image, while the green and brown areas are the actual locations of clutter scatterers and labels, respectively. Figure 4 (a) It can be seen that the present invention can accurately detect tags and clutter in the perception stage; Figure 4 As shown in (b), the present invention can further identify the tag, and the reconstruction result is consistent with the actual position, which verifies the effectiveness of the present invention in sensing tags and clutter scatterers and identifying tags.

[0132] Furthermore, the sensing area contains two tags and a copper clutter scatterer of equal size as the test object; see Figure 5 ,like Figure 5 As shown in (a), during the sensing phase, the two tags and clutter scatterers can be well detected; Figure 5 (b) and Figure 5 As shown in (c), each label can be identified separately; and both can be distinguished at the same time, such as Figure 5 (d) shown.

[0133] This solution demonstrates the backscatter communication function by demonstrating it in a scene containing tags and clutter scatterers. Specifically, the antenna voltage vector extracted in this example is The phase difference is π or , which verifies the transmission model under BPSK modulation. At the same time, by using MRC for 10 5 Monte Carlo simulations are performed to evaluate the bit error rate performance. Figure 6 ,As can be seen from the figure, the simulation results are in good agreement with the ,theoretical BER performance, which ,further verifies the reliability of this scheme in achieving the ,backscatter communication capability.

[0134] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the above-mentioned SAAs-based integrated sensing and backscatter communication method.

[0135] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the above-mentioned SAAs-based integrated sensing and backscattering communication method.

[0136] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0137] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0138] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0139] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0140] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0141] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. 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. An integrated sensing and backscatter communication method based on SAAs, characterized in that: Applied to an integrated sensing and backscattering communication system based on SAAs, the system includes transmitting SAAs, receiving SAAs and a sensing area, the sensing area includes tags and clutter scatterers, wherein the sensing area is discretized into N pixels, and the working bandwidth of the system is divided into frequency; the method comprising: Sending a pilot signal to the tag through the transmitting SAAs, modulating the load impedance of the tag at different frequencies so that the tag generates pilot signals in different modulation states, and backscattering the pilot signals in different modulation states to the receiving SAAs; The receiving SAAs receive pilot signals in different modulation states to obtain corresponding receiving voltages, and the combined voltage components associated with the structural modes of the clutter scatterer and the tag and the antenna voltage components associated with the antenna mode of the tag are calculated through the different receiving voltages; Measure the TE field measurement results of all pixel points in the sensing area at different frequencies to obtain a measurement matrix; estimating a first reflection coefficient vector and a second reflection coefficient vector based on the measurement matrix and the combined voltage components and antenna voltage components at all frequencies; The first reflection coefficient vector is used to sense clutter scatterers and tags, and the second reflection coefficient vector is used to identify tags from clutter scatterers.

2. The integrated sensing and backscatter communication method based on SAAs according to claim 1, characterized in that: The step of sending a pilot signal to the tag through the transmitting SAAs, modulating the load impedance of the tag so that the tag generates pilot signals in different modulation states, and backscattering the pilot signals in different modulation states to the receiving SAAs includes: sending a pilot signal to the tag via the transmitting SAAs; Under the BPSK modulation mode, the load impedance of the tag at different frequencies is modulated respectively so that the tag generates a pilot signal in an open circuit state and a pilot signal in a short circuit state; The pilot signal in the open circuit state and the pilot signal in the short circuit state are backscattered by the tag to the receiving SAAs.

3. The integrated sensing and backscattering communication method based on SAAs according to claim 2, characterized in that: The sensing area includes a tag and a clutter scatterer; the receiving SAAs receive pilot signals in different modulation states to obtain corresponding receiving voltages, and the steps of respectively calculating the combined voltage components associated with the structural modes of the clutter scatterer and the tag and the antenna voltage components associated with the antenna mode of the tag through the different receiving voltages include: The receiving SAAs receive pilot signals in different modulation states to obtain a receiving voltage of the pilot signal corresponding to an open circuit state and a receiving voltage of the pilot signal corresponding to a short circuit state; Calculate the average value of the sum of the received voltage of the pilot signal corresponding to the open circuit state and the received voltage of the pilot signal corresponding to the short circuit state to obtain a combined voltage component associated with the structural mode of the clutter scatterer and the tag; The average value of the difference between the received voltage of the pilot signal corresponding to the open circuit state and the received voltage of the pilot signal corresponding to the short circuit state is calculated to obtain the antenna voltage component associated with the antenna mode of the tag.

4. The integrated sensing and backscatter communication method based on SAAs according to claim 1, characterized in that: The first reflection coefficient vector and the second reflection coefficient vector are estimated based on the measurement matrix and the combined voltage components and antenna voltage components at all frequencies; Based on the combined voltage components and the antenna voltage components at all frequencies, a combined voltage component vector and an antenna voltage vector are constructed respectively; Establishing a linear relationship between the measurement matrix and the combined voltage component vector, and estimating a first reflection coefficient vector using a compressed sensing and two-step iterative shrinkage algorithm; A linear relationship between the measurement matrix and the antenna voltage component is established, and a second reflection coefficient vector is estimated by using compressed sensing and a two-step iterative shrinkage algorithm.

5. The SAAs-based integrated sensing and backscatter communication method according to claim 3, characterized in that: The received voltage is expressed as follows: Where: Indicates the frequency The receiving voltage under Indicates the frequency The combined voltage components associated with the structural modes of the clutter scatterers and the tag are shown below; Represents the reflection coefficient associated with the load impedance of the tag, Γ=1 means the tag is in an open circuit state, Γ=-1 means the tag is in a short circuit state; Indicates the frequency The antenna voltage component associated with the tag's antenna pattern; Then, under BPSK modulation, the combined voltage component associated with the structural mode of the clutter scatterer and the tag is It is expressed as: Where: Indicates the frequency The following is the received voltage of the pilot signal corresponding to the open circuit state, Indicates the frequency The receiving voltage of the pilot signal corresponding to the short-circuit state; Among them, the antenna voltage component associated with the tag's antenna mode is It is expressed as: 。 6. The SAAs-based integrated sensing and backscatter communication method according to claim 4, characterized in that: The process of establishing the linear relationship between the measurement matrix and the combined voltage component vector is expressed as follows: Where: represents the combined voltage component vector, where ; represents the measurement matrix; represents the first reflection coefficient vector, where ; The process of estimating the first reflection coefficient vector using compressed sensing and a two-step iterative shrinkage algorithm is expressed as follows: Where: ||·||1 is the l1 norm; The process of establishing the linear relationship between the measurement matrix and the antenna voltage component is expressed as follows: Where: represents the antenna voltage vector, where ; represents the second reflection coefficient vector, where ; The process of estimating the second reflection coefficient vector using compressed sensing and a two-step iterative shrinkage algorithm is expressed as follows: 。 7. The integrated sensing and backscatter communication method based on SAAs according to claim 1, characterized in that: The transmitting SAAs and the receiving SAAs both adopt a single-plane coupled waveguide cavity design and are mounted on a 0.508 mm Rogers RT5880 substrate.

8. The SAAs-based integrated sensing and backscatter communication method according to claim 1, characterized in that: The sizes of the transmitting SAAs and the receiving SAAs are both 186×165 mm; the spacing distance between the transmitting SAAs and the receiving SAAs on the x-axis is 40 mm.

9. A computer device, characterized in that: It comprises a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of the SAAs-based integrated sensing and backscatter communication method as described in any one of claims 1-8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the SAAs-based integrated sensing and backscatter communication method as described in any one of claims 1 to 8 are implemented.

Images