An Integrated Sensing and Backscatter Communication Method Based on SAAs

Abstract

The present invention discloses an integrated sensing and backscatter communication method based on SAAs, which is applied to an integrated sensing and backscatter communication system based on SAAs. In the present invention, sensing and backscatter communication are integrated with SAAs having a high scanning rate; by modulating the load impedance of the tag, the received 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 sensing of the tag and the clutter scatterer through the first reflection coefficient vector, and realizing tag identification through the second reflection vector; at the same time, due to the high scanning rate of SAAs, the system can achieve integrated communication functions with fewer antennas and a narrower operating bandwidth.

Description

Technical Field

[0001] The present invention relates to the field of communication technologies, and in particular, to an integrated sensing and backscatter 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 better utilize backscatter technology, Integrated Sensing and Communication (ISAC) has emerged. The communication system and the sensing system 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 dependence on phased arrays, mechanical, and electrical scanning mechanisms. By adopting a frequency diversity scheme, fast spatial data acquisition is achieved, thus eliminating the need for mechanical motion or active switching components, providing a promising electronic alternative for traditional imaging.

[0003] Antennas 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 achieving high-quality imaging within a few seconds. These technologies show great potential in providing high-fidelity imaging and accurate positioning reconstruction for clutter scatterers with time-invariant reflectivity. However, the above-mentioned microwave imaging systems have not yet achieved integrated communication, and in backscatter communication, some can only detect clutter scatterers, while some can only detect tags. Summary of the Invention

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

[0005] The present invention provides an integrated sensing and backscatter communication method based on SAAs, which is applied to an integrated sensing and backscatter communication system based on SAAs. The system includes transmitting SAAs, receiving SAAs, and a sensing area. The sensing area includes tags and clutter scatterers. The sensing area is discretized into N pixel points, and the working bandwidth of the system is divided into frequency bands; the method includes:

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

[0007] The receiving SAAs receive the pilot signals in different modulation states, obtain the corresponding received voltages, and respectively calculate 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 received voltages;

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

[0009] Based on the measurement matrix and the combined voltage components and antenna voltage components at all frequencies, estimate the first reflection coefficient vector and the second reflection coefficient vector respectively;

[0010] 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.

[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 in different modulation states, and backscattering the pilot signals in different modulation states to the receiving SAAs includes:

[0012] Send a pilot signal to the tag through the transmitting SAAs;

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

[0014] The tag backscatters the pilot signal in the open state and the pilot signal in the short state to the receiving SAAs.

[0015] More specifically, the sensing area includes a tag and a clutter scatterer; the step of the receiving SAAs receiving the pilot signals in different modulation states, obtaining the corresponding received voltages, and 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 includes:

[0016] The receiving SAAs receive the pilot signals in different modulation states, obtain the received voltage corresponding to the pilot signal in the open state and the received voltage corresponding to the pilot signal in the short 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, and obtain the combined voltage component associated with the structural mode of the clutter scatterer and the tag;

[0018] Calculate 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 obtain the antenna voltage component associated with the antenna mode of the tag.

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

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

[0021] Establish a linear relationship between the measurement matrix and the combined voltage component vector, and use compressive sensing and two-step iterative shrinkage algorithm to estimate the first reflection coefficient vector;

[0022] Establish a linear relationship between the measurement matrix and the antenna voltage component, and use compressive sensing and two-step iterative shrinkage algorithm to estimate the second reflection coefficient vector.

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

[0024]

[0025] Where: represents the received voltage at frequency , represents the combined voltage component associated with the structural mode of the clutter scatterer and the tag at frequency ; represents the reflection coefficient associated with the load impedance of the tag, Γ = 1 indicates that the tag is in the open circuit state, and Γ = -1 indicates that the tag is in the short circuit state; represents the antenna voltage component associated with the antenna mode of the tag at frequency ;

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

[0027]

[0028] Where: represents the received voltage of the pilot signal corresponding to the open circuit state at frequency ; Indicates the received voltage of the pilot signal corresponding to the short - circuit state at the frequency ;

[0029] Among them, the antenna voltage component associated with the antenna pattern of the tag 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] In the formula: 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 compressive sensing and two - step iterative shrinkage algorithm is expressed as follows:

[0036]

[0037] In the formula: ||·||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] In the formula: Represents the antenna voltage vector, where ; Represents the second reflection coefficient vector, where ;

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

[0042] .

[0043] More specifically, both the transmitting SAAs and the receiving SAAs 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. A computer program is stored in the memory. When the computer program is executed by the processor, the processor is caused to execute the steps of the integrated sensing and backscatter communication method based on SAAs as described in any one of the above.

[0046] The present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the integrated sensing and backscatter communication method based on SAAs as described in any one of the above are implemented.

[0047] From the above technical solutions, it can be seen that the present invention has the following advantages:

[0048] The present invention provides an integrated sensing and backscatter communication method based on SAAs, which is applied to an integrated sensing and backscatter communication system based on SAAs. The system includes transmitting SAAs, receiving SAAs, and a sensing area. The sensing area includes tags and clutter scatterers. The method includes: sending a pilot signal to the tags through the transmitting SAAs, modulating the load impedance of the tags at different frequencies so that the tags generate pilot signals in different modulation states, and backscattering the pilot signals in different modulation states to the receiving SAAs; receiving the pilot signals in different modulation states by the receiving SAAs to obtain corresponding received voltages, and respectively calculating a combined voltage component associated with the structural modes of the clutter scatterers and the tags and an antenna voltage component associated with the antenna mode of the tags through the different received voltages; measuring the 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; sensing the clutter scatterers and the tags using the first reflection coefficient vector, and identifying the tags from the clutter scatterers using the second reflection coefficient vector.

[0049] In the present invention, sensing and backscatter communication are integrated with SAAs having a high scanning rate; by modulating the load impedance of the tag, the received SAAs receive pilot signals in different modulation states to enhance backscattering, thereby calculating the combined voltage component and the antenna voltage component, and combining the measurement matrix to estimate the first reflection coefficient vector and the second reflection coefficient vector. The sensing of the tag and the clutter scatterer is achieved through the first reflection coefficient vector, and the tag identification is achieved through the second reflection vector. At the same time, due to the high scanning rate of the SAAs, the system can implement the integrated communication function with fewer antennas and a narrower operating bandwidth, thus solving the technical problems that the existing microwave imaging systems have not achieved integrated communication and it is difficult to accurately identify tags and clutter scatterers in backscatter communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0051] Figure 1 It is a flowchart of the steps of an integrated sensing and backscatter communication method based on SAAs provided by an embodiment of the present invention;

[0052] Figure 2 It is a model diagram of an integrated sensing and backscatter communication system based on SAAs provided by an embodiment of the present invention;

[0053] Figure 3 It is an effect diagram of the independent measurement ability of the system provided by an embodiment of the present invention within the operating bandwidth;

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

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

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

[0057] An embodiment of the present invention provides an integrated sensing and backscatter communication method based on SAAs, which is used to solve the technical problems that existing microwave imaging systems have not realized integrated communication, and it is difficult to accurately identify tags and clutter scatterers in backscatter communication.

[0058] In order to make the objectives, features, and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0059] Please refer to Figure 1 , a first aspect of the present invention provides an integrated sensing and backscatter communication method based on SAAs, including:

[0060] Step 101: Transmit a pilot signal to the tag by transmitting SAAs, modulate the load impedance of the tag at different frequencies so that the tag generates pilot signals in different modulation states, and backscatter the pilot signals in different modulation states to the receiving SAAs.

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

[0062] Specifically, please refer to Figure 2 , the system includes a transmit SAA (Transmit SAA), a receive SAA (Receive SAA), and a sensing area, where the transmit SAA and the receive SAA are arranged at intervals along the x-axis direction, and the interval distance is set as d. The sensing area refers to the spatial range where the system can perform sensing and detection. In Figure 2 the sensing area can be defined as a one-dimensional (1D) line area along the x-axis in the near-field region of the antenna.

[0063] The sensing area includes clutter scatterers with a fixed reflection coefficient and tags (Tags) that can change their reflectivity for backscatter communication. The sensing area is discretized into N uniform pixel points, and the interval between the pixel points is These pixel points are indexed by n, where n ∈ {1, 2, ..., N}; the operating bandwidth of the system is divided into N f frequency bands.

[0064] The main objective of the present invention is to accurately detect and distinguish these dynamic tags in a clutter environment. The present invention combines sparsity and inverse scattering techniques to enhance tag detection and recognition, and at the same time uses the maximum ratio combining (MRC) technique to extract the antenna pattern to obtain the channel state information (CSI), thereby enhancing backscatter communication.

[0065] This step specifically includes:

[0066] Sub-step 1011: Transmit pilot signals to the tags by transmitting SAAs.

[0067] Sub-step 1012: Under the BPSK modulation method, modulate the load impedance of the tags at different frequencies respectively so that the tags generate pilot signals in the open state and pilot signals in the short-circuit state.

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

[0069]

[0070] where: j = represents the imaginary unit, ω represents the angular frequency, represents the permeability of free space, represents the normalization constant, represents the position vector, represents the reflection coefficient; respectively represent the incident electric fields of the transmitting SAAs and the receiving SAAs at the location.

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

[0072] One part comes from the structural mode of the tag and the clutter scatterer, and the other part only comes from the antenna mode of the tag. Among them, the structural mode of the tag is not affected by the change of the tag load state, and this part is determined by the physical properties of the objects in the sensing area, such as shape, size, position, and material composition. In contrast, the antenna mode of the tag will change with the load impedance Z L of the tag.

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

[0074]

[0075] In the formula: Denotes the complex conjugate operation, Z A Is the antenna impedance of the SAAs, Denotes 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. To simplify and verify the integrated sensing and backscatter communication system, the present invention uses a 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 the open-circuit state, the load impedance tends to infinity, while the reflection coefficient approaches 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 mode of the tag shows a high-reflection state.

[0078] Sub-step 1013, backscatter 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 the inverse scattering technology to extract information about the tag and clutter scatterers from the signals received by the receiving SAAs. By adjusting the load impedance of the tag, signals in different states can be collected, and these signals can be used to reconstruct the positions and characteristics of the tag and clutter scatterers.

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

[0081] This step specifically includes:

[0082] Sub-step 1021, the receiving SAAs receive the pilot signals in different modulation states to obtain the received voltage corresponding to the pilot signal in the open-circuit state and the received voltage corresponding to the pilot signal in the short-circuit state.

[0083] It should be noted that in the case where the sensing area includes a tag and a clutter scatterer, Equation (1) can be expressed as the combined voltage component / constant component generated by the structural mode of the tag and the clutter scatterer where the reflection coefficient is expressed as and the variable component related to the tag antenna mode where the reflection coefficient is expressed as .

[0084] Therefore can be written as

[0085]

[0086] In the formula represents the reflection coefficient associated with the load impedance of the tag, Γ = 1 indicates that the tag is in an open circuit state, and Γ = -1 indicates that the tag is in a short circuit state; represents at frequency the antenna voltage component associated with the antenna mode of the tag

[0087] Similarly, the reflection coefficient presented at the position vector can be expressed as

[0088]

[0089] In the present invention, can be used to sense the clutter scatterer and the tag, and is used to identify the tag from the clutter scatterer. To separate and for accurate sensing and identification, in the BPSK modulation mode, the load impedance of the tag is modulated to be in an open circuit state and a short circuit state respectively, and the receiving voltages of different modulation states at different frequencies are recorded by the receiving SAAs:

[0090] The tag uses two pilot signals with reflection coefficients and for backscatter communication. According to Equation (3), the corresponding receiving voltages of the two pilot signals are given by

[0091] At frequency, the receiving voltage of the pilot signal corresponding to the open circuit state recorded by the receiving SAAs is expressed as

[0092]

[0093] At At the frequency, the received voltage of the pilot signal corresponding to the short - circuit state recorded by the received SAAs is expressed as follows:

[0094]

[0095] Sub - step 1022: 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, and obtain the combined voltage component associated with the structural mode of the clutter scatterer and the tag.

[0096] Then, at the frequency the combined voltage component associated with the structural mode of the clutter scatterer and the tag is expressed as:

[0097]

[0098] Sub - step 1023: Calculate 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 obtain the antenna voltage component associated with the antenna mode of the tag.

[0099] Then, at the frequency the antenna voltage component associated with the antenna mode of the tag is expressed as:

[0100]

[0101] Step 103: Measure 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 pixel points, 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. Therefore, the element H f in the n - th row and n - th column represents the electromagnetic field (TE - field) measurement result in the transverse electromagnetic wave mode at the n - th pixel point at the n - th frequency, which is: nf,n at the n - th f frequency and is:

[0103]

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

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

[0106] This step specifically includes:

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

[0108] It can be understood that for N f frequency measurements, the constructed combined voltage vector and the antenna voltage vector represent the received voltages of the tag structure mode and the clutter scatterer and the received voltage of the tag antenna mode respectively.

[0109] It should be noted that the present invention uses the maximum ratio combining (MRC) technique to process and combine the signals received from different frequencies by the receiving SAAs to improve the reliability and performance of backscatter communication. After combining the signals using the MRC technique, the combined voltage vector and the antenna voltage vector can be extracted. The change of the antenna voltage vector directly reflects the change of the load impedance of the tag, and these changes carry the channel state information (CSI). Subsequently, by analyzing the signal data of the antenna voltage vector these signals, the response state of the channel can be estimated, including characteristics such as the amplitude, phase, and polarization of the signal.

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

[0111] In this solution, the relative intensity of the received signal is mainly represented by the reflection coefficient. Therefore, the reflection coefficient contains key information about the target position and characteristics. Then, based on formula (1), the amplitude coefficient can be ignored (compared with the reflection coefficient, the amplitude coefficient shows a weaker intensity 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 as follows:

[0112]

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

[0114] Using compressive sensing and the two-step iterative shrinkage / thresholding algorithm, Equation (10) can be solved as follows:

[0115]

[0116] In this way, the first reflection coefficient vector can be estimated, but only using can only sense clutter scatterers and tags, which is not sufficient to identify tags from clutter scatterers. To further identify tags from clutter scatterers, it is necessary to use for tag identification. The and in the above Equations (10) and (11) can be swapped with and in turn to estimate , as shown in sub-step 1043.

[0117] In sub-step 1043, a linear relationship between the measurement matrix and the antenna voltage components is established, and the compressive sensing and two-step iterative shrinkage algorithm are used to estimate the second reflection coefficient vector.

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

[0119]

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

[0121] The process of using the compressive sensing and two-step iterative shrinkage algorithm to estimate the second reflection coefficient vector is shown as follows:

[0122]

[0123] It can be understood that generally there are only a few significant reflection coefficients in the sensing area. The present invention uses the compressive sensing and two-step iterative shrinkage / thresholding algorithm to recover the sparse signal from the limited measurement data, thus achieving accurate signal recovery.

[0124] In step 105, 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.

[0125] In this embodiment, the SAAs adopt a single-plane coupled waveguide cavity design. The SAAs are mounted on a 0.508 mm Rogers RT 5880 substrate, operate in the range of 3.975 - 4.025 GHz, and have dimensions of 186×165 mm. It achieves a return loss below -10 dB and maintains a radiation efficiency of 82%. In addition, the SAAs can 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, since the present invention does not rely on phased arrays, mechanical, and electrical scanning mechanisms, the imaging speed is faster and the complexity is greatly reduced; compared with existing MIMO schemes with communication functions, the number of antennas required for 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 range.

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

[0128] Exemplarily, a frequency-division integrated sensing and backscatter communication system with d = 40 mm is constructed using two SAAs. The sensing area spans 430 mm along the x-axis and is 50 mm away from the SAAs along the z-axis. This area is divided into N = 431 pixels with an interval of Δl = 1 mm. The frequency range from 3.975 to 4.025 GHz is sampled at intervals of 0.001 GHz, thus generating N f = 51 frequency samples; the measurement matrix H is collected by measuring the TE field at the positions of 431 pixel points at 51 frequencies.

[0129] Combined with the example, the present invention also provides simulation results based on comprehensive three-dimensional electromagnetic simulation, demonstrating the sensing, identification, and communication functions of this solution. Please refer to Figures 3 - 6 .

[0130] Singular value Decomposition (SVD) and sensing capacity techniques are usually used to evaluate the mode diversity ability of the proposed antenna; please refer to Figure 3 , Figure 3 demonstrates the ability of the antenna to perform independent measurements within the operating bandwidth, where Figure 3 (a) shows the singular value (normalized) spectral distribution of the system, while Figure 3(b) shows the sensing ability of the system, indicating that the system can achieve synchronous backscatter communication in a cluttered environment within a working bandwidth of 50 MHz.

[0131] Taking a sensing area containing a tag and a copper clutter scatterer of the same size as the test object, where the tag is specifically a copper dipole antenna with a radius of 10 mm and a height of 31.5 mm; please refer to Figure 4 , Figure 4 shows the sensing and recognition results of a single tag and a clutter scatterer. In Figure 4 , the blue line is the reconstructed image, while the green and brown areas are the actual positions of the clutter scatterer and the tag, respectively. As can be seen from Figure 4 (a), the present invention can accurately detect the tag and the clutter in the sensing stage; as shown in Figure 4 (b), the present invention can further identify the tag, and the reconstruction result is in good agreement with the actual position, which verifies the effectiveness of the present invention in sensing the tag and the clutter scatterer and identifying the tag.

[0132] Furthermore, taking a sensing area containing two tags and a copper clutter scatterer of the same size as the test object; please refer to Figure 5 , as shown in Figure 5 (a), in the sensing stage, two tags and the clutter scatterer can be well detected; as shown in Figure 5 (b) and Figure 5 (c), each tag can also be individually identified; and the two can be distinguished simultaneously, as shown in Figure 5 (d).

[0133] This solution demonstrates the backscatter communication function by demonstrating in a scenario containing tags and clutter scatterers. Specifically, in this example, the antenna voltage vectors extracted are consistent in the open-circuit state and the short-circuit state, and the phase difference is π or , which verifies the transmission model under BPSK modulation. At the same time, the bit error rate performance is evaluated by using MRC for 10 5 Monte Carlo simulations; please refer to Figure 6 . As can be seen from the figure, the simulation results are in good agreement with the theoretical bit error rate performance, further verifying the reliability of the ability of this solution to achieve backscatter communication.

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

[0135] The present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-described SAAs-based integrated sensing and backscatter communication method are implemented.

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

[0137] In several embodiments provided by 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 merely illustrative. For example, the division of the units is only a logical function division, and there can be other division methods in actual implementation. For example, 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 displayed or discussed couplings or direct couplings or communication connections to each other can be indirect couplings or communication connections through some interfaces, devices, or units, and can be in electrical, mechanical, or other forms.

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

[0139] In addition, in each embodiment of the present invention, the functional units can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated units can 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 this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0141] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various 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 backscatter communication system based on SAAs, the system includes transmitting SAAs, receiving SAAs, and a sensing area, the sensing area includes tags and clutter scatterers, where the sensing area is discretized into N pixel points, and the operating bandwidth of the system is divided into frequencies; the method includes: Send a pilot signal to the tag through the transmitting SAAs, modulate the load impedance of the tag at different frequencies so that the tag generates pilot signals in different modulation states, and backscatter the pilot signals in different modulation states to the receiving SAAs; Receive the pilot signals in different modulation states by the receiving SAAs, obtain the corresponding received voltages, and calculate 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 respectively through the different received voltages; Measure the TE field measurement results of all pixel points in the sensing area at different frequencies to obtain a measurement matrix; Estimate the first reflection coefficient vector and the second reflection coefficient vector respectively based on the measurement matrix and the combined voltage components and antenna voltage components at all frequencies; Sense the clutter scatterer and the tag using the first reflection coefficient vector, and identify the tag from the clutter scatterer using the second reflection coefficient vector.

2. The integrated sensing and backscatter communication method based on SAAs according to claim 1, wherein 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: Send a pilot signal to the tag through the transmitting SAAs; Under the BPSK modulation method, modulate the load impedance of the tag at different frequencies respectively so that the tag generates a pilot signal in an open state and a pilot signal in a short state; Backscatter the pilot signal in the open state and the pilot signal in the short state to the receiving SAAs through the tag.

3. The integrated sensing and backscatter communication method based on SAAs according to claim 2, wherein The sensing area includes a tag and a clutter scatterer; the step of receiving the pilot signals in different modulation states by the receiving SAAs, obtaining the corresponding received 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 respectively includes: Receive the pilot signals in different modulation states by the receiving SAAs, and obtain the received voltage corresponding to the pilot signal in the open state and the received voltage corresponding to the pilot signal in the short state; Calculate the average value of the sum of the received voltage corresponding to the pilot signal in the open state and the received voltage corresponding to the pilot signal in the short state to obtain the combined voltage components associated with the structural modes of the clutter scatterer and the tag; Calculate the average value of the difference between the received voltage corresponding to the pilot signal in the open state and the received voltage corresponding to the pilot signal in the short state to obtain the antenna voltage components associated with the antenna mode of the tag.

4. The integrated sensing and backscatter communication method based on SAAs according to claim 1, wherein Based on the measurement matrix and the combined voltage components and antenna voltage components at all frequencies, estimate the first reflection coefficient vector and the second reflection coefficient vector respectively; Construct a combined voltage component vector and an antenna voltage vector respectively based on the combined voltage components and antenna voltage components at all frequencies; Establish a linear relationship between the measurement matrix and the combined voltage component vector, and use compressive sensing and two-step iterative shrinkage algorithm to estimate the first reflection coefficient vector; A linear relationship between the measurement matrix and the antenna voltage components is established, and the second reflection coefficient vector is estimated using compressive sensing and a two-step iterative shrinkage algorithm.

5. The integrated sensing and backscatter communication method based on SAAs according to claim 3, wherein The received voltage is expressed as follows: Wherein: represents the received voltage at the frequency ; represents the combined voltage component associated with the structural modes of the clutter scatterer and the tag at the frequency ; represents the reflection coefficient associated with the load impedance of the tag, Γ = 1 indicates that the tag is in an open state, and Γ = -1 indicates that the tag is in a short - circuit state; represents the antenna voltage component associated with the antenna mode of the tag at the frequency ; Then, under the BPSK modulation method, the combined voltage component associated with the structural patterns of the clutter scatterers and the tags is expressed as: Wherein: represents the received voltage of the pilot signal corresponding to the open circuit state at the frequency ; represents the received voltage of the pilot signal corresponding to the short circuit state at the frequency ; wherein, an antenna voltage component associated with an antenna pattern of a tag is expressed as: 。 6. The integrated sensing and backscatter communication method based on SAAs according to claim 4, wherein The process of establishing the linear relationship between the measurement matrix and the combined voltage component vector is expressed as follows: In the formula: 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 compressive 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 components is expressed as follows: Wherein: represents the antenna voltage vector, where ; represents the second reflection coefficient vector, where ; The process of estimating the second reflection coefficient vector using compressive 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, Both the transmitting SAAs and the receiving SAAs adopt a single-plane coupled waveguide cavity design and are mounted on a 0.508 mm Rogers RT5880 substrate.

8. The integrated sensing and backscatter communication method based on SAAs according to claim 1, characterized in that The sizes of both the transmitting SAAs and the receiving SAAs are 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 includes a memory and a processor. When the computer program stored in the memory is executed by the processor, the processor executes the steps of the integrated sensing and backscatter communication method based on SAAs according to 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 the processor, it implements the steps of the integrated sensing and backscatter communication method based on SAAs according to any one of claims 1-8.

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