Target detection method and device based on coprime subcarriers, equipment and medium

Abstract

The application discloses a target detection method and device based on a co-prime OFDM subcarrier pulse sensing waveform, equipment and a medium, the method comprises the following steps: determining a co-prime factor number pair according to the communication parameters in the 5G-NR integrated sensing scene, and determining a co-prime OFDM subcarrier index set used in the sensing scene; a baseband signal model of the co-prime OFDM subcarrier pulse sensing waveform is established, and a radio frequency signal of the co-prime OFDM subcarrier pulse sensing baseband signal waveform is radiated outward; according to the vehicle target scene, the baseband echo signal model of the co-prime OFDM subcarrier pulse sensing waveform and the echo signal model of the equivalent subcarrier are constructed, the echo signal is processed, and a time delay-Doppler two-dimensional matrix is obtained; the technical scheme of the embodiment of the application can meet the bandwidth constraint greatly, use the lowest possible spectrum resource consumption for sensing, and accurately and effectively realize low-complexity target detection.

Description

Technical Field

[0001] This invention relates to the field of integrated sensing target detection technology, and in particular to a target detection method based on coprime OFDM subcarrier pulse sensing waveform, a target detection device based on coprime OFDM subcarrier pulse sensing waveform, an electronic device, and a computer-readable storage medium. Background Technology

[0002] Integrated Radar Sensing and Communication (ISAC) technology is a key technology in 5G NR (New Radio) and next-generation wireless networks. This technology achieves dual functions of target sensing and wireless communication by sharing hardware systems and wireless spectrum, showing significant application prospects in fields such as intelligent transportation, smart homes, and security and surveillance. Compared to traditional, separate communication and radar technologies, integrated radar sensing and communication technology not only increases system feasibility but also reduces system cost and complexity. However, in practical applications, ISAC waveform design remains a critical issue.

[0003] In 5G NR systems, the ISAC system utilizes traditional Orthogonal Frequency Division Multiplexing (OFDM) communication signals for integrated sensing and communication, representing a typical approach to achieving dual communication and sensing functions. It fully leverages the multi-subcarrier diversity of OFDM communication systems, the high range resolution of OFDM radar, and the range-Doppler decoupling characteristics. To date, researchers have proposed sensing algorithms based on OFDM signals for integrated sensing and communication. These algorithms utilize the range-Doppler decoupling characteristics of OFDM echo signals and employ Discrete Fourier Transform (DFT) and Inverse Discrete Fourier Transform (IDFT) to estimate target range and velocity parameters, respectively. To improve the accuracy of parameter estimation, researchers model OFDM sensing signals as multi-channel signals and utilize subspace algorithms to achieve high-resolution estimation of range and velocity. Furthermore, to utilize spatial degrees of freedom information, integrated sensing and communication waveform design methods under MIMO systems have emerged.

[0004] In the process of realizing this invention, the inventors discovered that all existing technologies require continuous subcarriers for integrated sensing waveform design. When subcarriers are discontinuous, the existing integrated sensing algorithms are severely degraded or even unusable. Therefore, when spectrum resources are scarce or when there is a discontinuous distribution of available subcarriers due to large-scale users, accurate and efficient target sensing services cannot be provided. Summary of the Invention

[0005] This invention provides a target detection based on coprime OFDM subcarrier pulse sensing waveforms, a target detection device based on coprime OFDM subcarrier pulse sensing waveforms, an electronic device, and a computer-readable storage medium. While greatly satisfying bandwidth constraints, it uses the lowest possible sensing spectrum resource overhead to accurately and effectively achieve low-complexity target detection.

[0006] According to one aspect of the present invention, a target detection method based on coprime OFDM subcarrier pulse sensing waveform is provided, comprising:

[0007] Based on the communication parameters in the 5G-NR sensing integration scenario, determine the number of coprime factor pairs, and based on the number of coprime factor pairs, determine the coprime OFDM subcarrier index set used in the sensing scenario;

[0008] Based on the coprime OFDM subcarrier index set, a baseband signal model of the coprime OFDM subcarrier pulse sensing waveform is established. After generating a coprime OFDM subcarrier pulse sensing baseband signal waveform that matches the baseband signal model, the radio frequency signal of the coprime OFDM subcarrier pulse sensing baseband signal waveform is radiated to the surrounding environment.

[0009] Based on the vehicle target scenario, a baseband echo signal model and an equivalent subcarrier echo signal model of the coprime OFDM subcarrier pulse sensing waveform are constructed. The echo signal is processed to obtain a time delay-Doppler two-dimensional matrix for target detection.

[0010] In this time-delay-Doppler two-dimensional matrix, each matrix element is used to describe the echo signal power value under a set time delay and a set Doppler frequency.

[0011] According to another aspect of the present invention, a target detection device based on coprime OFDM subcarrier pulse sensing waveform is also provided, comprising:

[0012] The coprime subcarrier determination module is used to determine the number of coprime factor pairs based on the communication parameters in the 5G-NR integrated sensing scenario, and to determine the coprime OFDM subcarrier index set used in the sensing scenario based on the number of coprime factor pairs.

[0013] The coprime subcarrier waveform construction module is used to establish a baseband signal model of the coprime OFDM subcarrier pulse sensing waveform based on the coprime OFDM subcarrier index set, and after generating a coprime OFDM subcarrier pulse sensing baseband signal waveform that matches the baseband signal model, radiate the radio frequency signal of the coprime OFDM subcarrier pulse sensing baseband signal waveform to the surrounding environment.

[0014] The echo signal processing module is used to process the echo signal based on the baseband echo signal model and the equivalent subcarrier echo signal model of the coprime OFDM subcarrier pulse sensing waveform constructed according to the vehicle target scene, and to obtain the time delay-Doppler two-dimensional matrix for target detection.

[0015] In this time-delay-Doppler two-dimensional matrix, each matrix element is used to describe the echo signal power value under a set time delay and a set Doppler frequency.

[0016] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0017] At least one processor; and

[0018] A memory communicatively connected to the at least one processor; wherein,

[0019] The memory stores a computer program that can be executed by the at least one processor, which enables the at least one processor to perform the target detection method based on coprime OFDM subcarrier pulse sensing waveform according to any embodiment of the present invention.

[0020] According to another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing computer instructions, the computer instructions being configured to cause a processor to execute and implement the target detection method based on coprime OFDM subcarrier pulse sensing waveforms as described in any embodiment of the present invention.

[0021] The technical solution of this invention constructs a low-overhead coprime OFDM subcarrier pulse sensing baseband signal waveform and uses this coprime OFDM subcarrier pulse sensing baseband signal to modulate a radio frequency signal for target detection. Based on the vehicle target scenario, a baseband echo signal model of the constructed coprime OFDM subcarrier pulse sensing waveform and an echo signal model of the equivalent subcarrier are used to perform digital signal processing on the echo signal to obtain a time-delay-Doppler two-dimensional matrix implementation method for target detection. This can effectively alleviate the problem of spectrum resource scarcity and the discontinuous distribution of available subcarriers caused by large-scale users. It achieves sensing performance close to that achieved when using continuous carriers while greatly satisfying bandwidth constraints and using the lowest possible spectrum resource overhead for sensing.

[0022] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a flowchart of a target detection method based on coprime OFDM subcarrier pulse sensing waveform provided in Embodiment 1 of the present invention;

[0025] Figure 2 This is a schematic diagram of a target vehicle perception scenario applicable to an embodiment of the present invention;

[0026] Figure 3 This is a frequency occupancy comparison diagram applicable to the technical solution of this embodiment of the invention;

[0027] Figure 4 This is a comparison diagram of a distance-dimensional fuzzy function to which the technical solution of this embodiment of the invention applies;

[0028] Figure 5 This is a comparative diagram of target detection results obtained by different methods applicable to the technical solutions of this embodiment of the invention;

[0029] Figure 6 This is a comparative schematic diagram of distance dimension cross-sectional images obtained by different methods applicable to the technical solutions of this embodiment of the invention;

[0030] Figure 7 This is a structural diagram of a target detection device based on coprime OFDM subcarrier pulse sensing waveform provided in Embodiment 2 of the present invention;

[0031] Figure 8 This is a schematic diagram of the structure of an electronic device that implements a target detection method based on coprime OFDM subcarrier pulse sensing waveform according to an embodiment of the present invention. Detailed Implementation

[0032] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0033] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0034] Example 1

[0035] Figure 1 This is a flowchart of a target detection method based on coprime OFDM subcarrier pulse sensing waveform provided in Embodiment 1 of the present invention. This embodiment is applicable to the situation where a 5G-NR base station transmits a radio frequency signal of coprime OFDM subcarrier pulse sensing baseband signal waveform for target detection. This method can be executed by a target detection device based on coprime OFDM subcarrier pulse sensing waveform. This device can be implemented in hardware and / or software and is generally configured in a single-site OFDM pulse radar system. Figure 1 As shown, the method includes:

[0036] S110. Based on the communication parameters in the 5G-NR sensing integration scenario, determine the number of coprime factor pairs, and based on the number of coprime factor pairs, determine the coprime OFDM subcarrier index set used in the sensing scenario.

[0037] Among them, the 5G-NR (New Radio) integrated sensing scenario can be understood as all OFDM subcarrier resources that can be used under the 5G New Radio communication protocol, which can be used for both sensing and communication scenarios.

[0038] The communication parameters can be understood as various standard communication parameters used in the 5G-NR communication protocol, such as OFDM signal bandwidth and subcarrier spacing. Coprime factor pairs can be understood as two coprime factors that are mutually prime. These two coprime factors can be used to identify multiple sets of coprime OFDM subcarriers in a series of consecutive OFDM subcarriers for use in sensing scenarios. The coprime OFDM subcarrier index set can be understood as the set of index numbers of coprime OFDM subcarriers within a series of consecutive subcarriers.

[0039] In an optional implementation of this embodiment, determining the coprime factor pairs based on the communication parameters in the 5G-NR integrated sensing scenario may include:

[0040] Based on the OFDM signal bandwidth and subcarrier spacing in the 5G-NR integrated sensing scenario, calculate the total number of subcarriers N. s ;

[0041] According to the formula: {(M,N)|(2M-1)N≤N s Let (M,N)=1}, then determine the number of coprime factor pairs M and N; where (M,N)=1 represents that the greatest common divisor between M and N is 1.

[0042] In a specific example, if the OFDM signal bandwidth is B and the subcarrier spacing is Δf, then the total number of subcarriers is... Furthermore, in a 5G-NR integrated sensing scenario, when bandwidth B = 100MHz, Δf = 60KHz, N s =1666.

[0043] Furthermore, using the formulas described above for determining the number of coprime factor pairs M and N, we can calculate M = 8 and N = 111.

[0044] In another optional implementation of this embodiment, determining the coprime OFDM subcarrier index set used in the sensing scenario based on coprime factor pairs may include:

[0045] According to the formula: Determine the coprime OFDM subcarrier index set used in the sensing scenario

[0046] Continuing the previous example, when M=8 and N=111, the coprime OFDM subcarrier index set It can be represented as:

[0047]

[0048] Meanwhile, coprime OFDM subcarrier index set The number of elements contained therein is the total number N of OFDM subcarriers used in the sensing scene. cop , where N cop =2M + N - 1 = 126. Simultaneously, the bandwidth B occupied by the perceived scene can also be calculated. cop B cop =N cop ×Δf=126×60=7.56(MHz), and the percentage of bandwidth occupied by the sensing scene to the total bandwidth ρ:

[0049] N obtained from the above calculation cop As can be seen from ρ, in the sensing scenario of 5G-NR integrated sensing, the problem of spectrum resource shortage in the integrated sensing system can be effectively reduced, and the overhead of spectrum resources for sensing can be minimized.

[0050] S120. Based on the coprime OFDM subcarrier index set, establish a baseband signal model of the coprime OFDM subcarrier pulse sensing waveform, and after generating a coprime OFDM subcarrier pulse sensing baseband signal waveform that matches the baseband signal model, radiate the radio frequency signal of the coprime OFDM subcarrier pulse sensing baseband signal waveform to the surrounding environment.

[0051] Based on the coprime OFDM subcarrier index set, establishing a baseband signal model for the coprime OFDM subcarrier pulse sensing waveform can include:

[0052] According to the formula:

[0053] Constructing a baseband signal model s for coprime OFDM subcarrier pulse sensing waveform cop (t);

[0054] Where, N u N represents the number of pulses within a frame. cop c represents the number of coprime OFDM subcarriers in the coprime OFDM subcarrier index set. k,u p represents the modulation symbol of the k-th subcarrier and the u-th pulse. k This represents the index number of the k-th subcarrier in the coprime OFDM subcarrier index set, where Δf is the subcarrier spacing, and T... r The pulse repetition period is represented by T, which is the duration of one OFDM symbol. rect(·) represents a rectangular pulse.

[0055] Specifically, N u , Δf, T r Both T and c are known communication parameters in the 5G-NR integrated sensing scenario. k,uThis is the modulated signal obtained by adjusting a known signal using subcarriers.

[0056] In this embodiment, after establishing the baseband signal model of the coprime OFDM subcarrier pulse sensing waveform, a coprime OFDM subcarrier pulse sensing baseband signal waveform matching the baseband signal model can be constructed first. Then, the coprime OFDM subcarrier pulse sensing baseband signal waveform is subjected to signal modulation processing to obtain a radio frequency signal conforming to the 5G-NR communication protocol. The radio frequency signal is then radiated to the surrounding environment through the base station's transmitting antenna for target detection.

[0057] Specifically, in Figure 2 The diagram illustrates a target vehicle perception scenario applicable to an embodiment of the present invention. Figure 2 As shown, 5N-NR base stations applied to sensing scenarios (such as...) Figure 2 The ISAC BS shown is placed on a roadside gantry. The 5G-NR base station uses the radio frequency signal radiated by the coprime OFDM subcarrier pulse to sense the baseband signal waveform in the surrounding environment. The position and speed of the target vehicle can be detected by the echo signal reflected back from the target vehicle.

[0058] S130. Based on the vehicle target scenario, construct the baseband echo signal model and the equivalent subcarrier echo signal model of the coprime OFDM subcarrier pulse sensing waveform, process the echo signal to obtain the time delay-Doppler two-dimensional matrix for target detection.

[0059] In this time-delay-Doppler two-dimensional matrix, each matrix element is used to describe the echo signal power value under a set time delay and a set Doppler frequency.

[0060] In an optional implementation of this embodiment, based on the vehicle target scene, a baseband echo signal model of the coprime OFDM subcarrier pulse sensing waveform and an echo signal model of the equivalent subcarrier are constructed. The echo signal is then processed to obtain a time-delay-Doppler two-dimensional matrix for target detection, which may include:

[0061] S1301. In the vehicle target scenario, by modeling the moving vehicle as a multi-scattering point model, the baseband echo signal model of the coprime OFDM subcarrier pulse sensing waveform is constructed as follows:

[0062]

[0063] Where Q represents the number of vehicle targets, N t β represents the number of reflection points of the target vehicle. q,iThis represents the backward complex amplitude of the i-th reflection point in the q-th vehicle. R represents the delay of the echo from the i-th reflection point in the q-th vehicle. i Let be the distance from the i-th reflection point to the signal source; v represents the Doppler frequency of the echo from the i-th target in the q-th vehicle. q,i Let λ be the velocity of the i-th reflection point in the q-th vehicle, λ be the wavelength of the electromagnetic wave, c0 represent the propagation speed of the electromagnetic wave, and w(t) represent the ground clutter and receiver thermal noise components.

[0064] The symbols not fully described in this formula can be found in the symbol representation of the baseband signal model of the coprime OFDM subcarrier pulse sensing waveform.

[0065] S1302. Based on the baseband echo signal model of the coprime OFDM subcarrier pulse sensing waveform, perform cyclic prefix removal, subcarrier separation, and modulation symbol removal processing on the echo signal in sequence, and then process according to the sampling interval. The processed baseband echo signal is sampled to obtain the echo matrix Y of the physically coprime OFDM subcarrier pulse sensing signal. cop .

[0066] Among them, the baseband echo signal (Y) of the u-th pulse and the k-th subcarrier cop ) u,k Represented as:

[0067]

[0068] Among them, Y cop N represents u ×N cop The echo matrix of the physically coprime OFDM subcarrier pulse sensing signal, (W1) u,k This indicates that w(t) has undergone cyclic prefix removal, subcarrier separation, modulation symbol removal, and time-domain sampling to obtain the baseband ground clutter and receiver thermal noise components of the u-th pulse and the k-th subcarrier.

[0069] Optionally, cyclic prefix removal can be understood as truncating the received echo signal according to a preset time length, obtaining only the echo signal after removing the cyclic prefix for subsequent processing; subcarrier separation can be understood as performing OFDM subcarrier demodulation on the echo signal; and modulation symbol removal can be understood as dividing the demodulated echo signal by the modulation symbol c. k,u The process involves removing modulation symbols from the echo signal. After sequentially performing cyclic prefix removal, subcarrier separation, and modulation symbol removal on the echo signal, the resulting signal is called the baseband echo signal.

[0070] In an optional implementation of this embodiment, the total number of subcarriers N can be used as a reference. s And the subcarrier spacing Δf, determine the pulse spacing Δt, and use the pulse spacing Δt as the sampling interval to sample the echo processing signal, and then sample the N... u ×N cop Using sampling points, the echo matrix Y of the physically coprime OFDM subcarrier pulse sensing signal is constructed. cop .

[0071] S1303, According to the formula: The difference set of index numbers is calculated.

[0072] S1304, after removing the difference set The duplicate values ​​are identified, and after sorting each difference set element in ascending order, the index number of each equivalent subcarrier is obtained.

[0073] Specifically, an equivalent subcarrier echo signal matrix can be constructed based on the index difference set of the coprime subcarriers and the echo matrix of the physical OFDM coprime subcarrier pulse sensing signal.

[0074] S1305, Regarding matrix Y cop Each row element Y cop (m,:), m=1,…,N u Perform the following operations:

[0075] Among them, Y cop (m,:), m=1,…,N u , representing matrix Y cop The element in the m-th row;

[0076] According to the equivalent subcarrier index number With R cop,m Based on the correspondence of the positions of the elements, the equivalent subcarrier index number is selected. The corresponding elements form the echo signal of the equivalent subcarrier pulse sensing, and finally obtain The echo matrix Y of the equivalent subcarrier sensing pulse v ;

[0077] Wherein, the echo matrix Y v The signal of the u-th pulse and the l-th equivalent subcarrier is represented as follows:

[0078]

[0079] Among them, (Y) v ) u,l Y represents the echo signal of the sensing waveform of the u-th pulse and the l-th equivalent subcarrier pulse.v express The echo matrix of the equivalent subcarrier pulse sensing waveform, σ q,i =|β q,i | 2 This represents the power of the i-th reflection point in the q-th vehicle. W1 represents the index number of the l-th equivalent subcarrier, and W2 represents the equivalent ground clutter and receiver thermal noise components.

[0080] Specifically, R cop,m Represents matrix Y cop The calculation result is obtained by multiplying each element of a row by the torque of the corresponding element in that row, and then obtaining the R. cop,m Then, the matrix can be further vectorized and redundancy removed, and then processed according to the equivalent subcarrier index number. With R cop,m Based on the correspondence of the positions of the elements, the equivalent subcarrier index number is selected. The corresponding elements form the echo signal of the equivalent subcarrier pulse sensing, which can be obtained. The echo matrix Y of the equivalent subcarrier sensing pulse v Generally speaking, the echo matrix Y of the equivalent subcarrier sensing pulse v The number of columns, that is It will be much greater than N cop .

[0081] S1306. Based on the echo matrix Y of the equivalent subcarrier sensing pulse... v and the index number of each equivalent subcarrier. The time-delay-Doppler two-dimensional matrix used for target detection is obtained.

[0082] In an optional implementation of this embodiment, based on the echo matrix Y of the equivalent subcarrier sensing pulse... v and the index number of each equivalent subcarrier. The time-delay-Doppler two-dimensional matrix used for target detection can include:

[0083] Based on the index number of each equivalent subcarrier Determine the longest consecutive subcarrier number; based on the longest consecutive subcarrier number, in the echo matrix Y of the equivalent subcarrier sensing pulse... v Extracting the local echo matrix of the equivalent subcarrier sensing pulse. First, the local echo matrix of the equivalent subcarrier sensing pulse is analyzed. After performing an inverse discrete Fourier transform on each row, a Doppler dimension matrix is ​​obtained; then, a discrete Fourier transform is performed on each column of the Doppler dimension matrix to obtain the time delay-Doppler two-dimensional matrix.

[0084] In this process, the elements of each difference set are sorted in ascending order to obtain the index number of each equivalent subcarrier. Then, we can obtain the index numbers of the equivalent subcarriers in the form of 1, 2, 3, 4, 5, 6, 8, 9, 10, 15. Furthermore, the number of the longest consecutive subcarriers mentioned above is the number of consecutive subcarriers obtained by traversing from the first index, that is, 6 in total, 1, 2, 3, 4, 5, 6.

[0085] As mentioned earlier, the echo matrix Y of the equivalent subcarrier sensing pulse v The number of columns is much larger than the echo matrix Y of the physically coprime OFDM subcarrier pulse sensing signal. cop The number of columns is such that, therefore, to ensure the best target detection performance, the echo matrix Y of the equivalent subcarrier sensing pulse can be... v A continuous column matching the number of longest consecutive subcarriers is extracted from the data to form the local echo matrix of the equivalent subcarrier sensing pulse. Considering the echo matrix Y of the equivalent subcarrier sensing pulse with the middle column number v It has good performance and is optional; it can sense the echo matrix Y of the pulse from the equivalent subcarrier. v Starting from the middle column, select columns forward and backward by (number of longest consecutive subcarriers / 2) to finally obtain the local echo matrix of the equivalent subcarrier sensing pulse.

[0086] The local echo matrix of the equivalent subcarrier sensing pulse is obtained. Then, the local echo matrix of the equivalent subcarrier sensing pulse can be analyzed first. After performing an inverse discrete Fourier transform (IDFT) on each row, the time delay dimension matrix is ​​obtained. Then, a discrete Fourier transform (DFT) is performed on each column of the time delay dimension matrix to obtain the time delay-Doppler two-dimensional matrix, represented as:

[0087]

[0088] Here, IDFT(·, 2) represents performing IDFT on each row, and DFT(·, 1) represents performing DFT on each column.

[0089] The technical solution of this invention constructs a low-overhead coprime OFDM subcarrier pulse sensing waveform and uses this waveform to construct a radio frequency signal for target detection. Based on the vehicle target scenario, the baseband echo signal model and the equivalent subcarrier echo signal model of the constructed coprime OFDM subcarrier pulse sensing waveform are used to perform digital signal processing on the echo signal, resulting in a delay-Doppler two-dimensional matrix implementation for target detection. This effectively alleviates the problem of spectrum resource scarcity and discontinuous distribution of available subcarriers in large-scale user scenarios. It achieves sensing performance close to that achieved when using continuous carriers, while greatly satisfying bandwidth constraints and using the lowest possible spectrum resource overhead for sensing.

[0090] Based on the above embodiments, after obtaining the time-delay-Doppler two-dimensional matrix for target detection, it may further include:

[0091] The time delay dimension information τ in the time delay-Doppler two-dimensional matrix is ​​converted into distance dimension information R, and the Doppler frequency dimension information f in the time delay-Doppler two-dimensional matrix is ​​also converted. d After converting to velocity dimension information v, a distance-velocity two-dimensional matrix is ​​obtained;

[0092] The maximum value matrix element in the distance-velocity two-dimensional matrix is ​​obtained by traversing the matrix, and the target distance and target velocity corresponding to the maximum value matrix element are determined as the target detection result.

[0093] As mentioned earlier, after obtaining the time-delay-Doppler two-dimensional matrix for target detection, each matrix element in the time-delay-Doppler two-dimensional matrix is ​​used to describe the signal amplitude under a set time delay and a set Doppler frequency. Therefore, it is necessary to first convert the matrix dimension information.

[0094] Specifically, we can first use the delay calculation formula. Calculate the distance R and use the Doppler calculation formula. By calculating the velocity v, the delay-Doppler two-dimensional matrix can be converted into a distance-velocity two-dimensional matrix. Then, by scanning this distance-velocity two-dimensional matrix, the target vehicle's distance to the 5G-NR base station and its target velocity can be detected.

[0095] To further illustrate the beneficial effects of this invention compared to the prior art, Monte Carlo simulations are used to demonstrate the beneficial effects of various embodiments of this invention in terms of occupied frequency bandwidth, resolution performance, and target detection.

[0096] In the simulation, we set the following parameters: the proposed 5G NR sensing-integrated waveform is used in intelligent transportation scenarios, and its sensing-integrated function is integrated at the base station; the sensing radar is placed on a gantry above the road at a height h = 7m; considering the subcarrier spacing is Δf = 60kHz, one radio frame is 10ms, which is the pulse coherence processing duration, and the pulse width of the sensing radar is one OFDM symbol duration, i.e., T = 16.67us; the uniform pulse repetition period T r = 0.125ms, number of pulses N u =80, number of subcarriers N s =1666, Number of coprime subcarriers N cop =126, OFDM signal bandwidth is B=100MHz, OFDM carrier center frequency is 26GHz. Assume receiver thermal noise follows an independent zero-mean complex Gaussian distribution with noise variance of 1; ground clutter follows a zero-mean complex Gaussian distribution with clutter-to-noise ratio (CNR) of 30dB, and ground clutter is considered to have internal clutter motion caused by wind speed, with wind speed of 2m / s.

[0097] First, we compared the bandwidth occupied by the OFDM sensing waveform of the proposed coprime sub-carriers (CPC) with that of the OFDM sensing waveform of traditional uniform sub-carriers (UNC). The results are as follows: Figure 3 As shown. In the simulation, the OFDM signal bandwidth of 100MHz corresponds to a frequency range of -50MHz to 50MHz.

[0098] in, Figure 3 This is a frequency occupancy comparison diagram applicable to the technical solution of this embodiment of the invention. Figure 3 The left side is a schematic diagram of the bandwidth occupancy of the CPC-based OFDM sensing waveform. Figure 3 The right side of the diagram shows the bandwidth occupancy of the OFDM sensing waveform based on UNC. Figure 3 It is evident that, compared to UNC, the proposed CPC is largely empty, meaning there are many unused subcarrier frequency bands. Therefore, these unused frequency resources can be used for communication, significantly reducing the overhead of sensing frequency resources.

[0099] Next, we compared the proposed virtual equivalent coprime waveform (VIC) with the distance dimension ambiguity function of UNC, and the results are as follows: Figure 4 As shown.

[0100] in, Figure 4 This is a comparison diagram of a distance-dimensional fuzzy function to which the technical solution of this embodiment of the invention applies. Figure 4 The left part is a distance-dimensional ambiguity function of the virtual equivalent coprime waveform. Figure 4 The right-hand side is the distance-dimensional fuzzy function of UNC. (Through...) Figure 4 It is evident that our proposed VIC and UNC have the same maximum unambiguous distance range, and the peak-sidelobe ratio (PSLR) and integral-sidelobe ratio (ISLR) of VIC are close to those of UNC. This indicates that the proposed coprime subcarrier sensing method can achieve sensing performance close to that of the traditional full-bandwidth OFDM sensing method, while occupying only 7.56% of the bandwidth (calculated in the aforementioned embodiments).

[0101] Then, we compared the target detection performance of the proposed algorithm. Figure 5 This is a schematic diagram comparing the target detection results of two vehicle targets at different distances and speeds obtained by different methods applicable to the technical solution of this invention. It includes: Figure 5 The leftmost part shows a schematic diagram of the target detection results of the sensing method based on equivalent coprime subcarriers combined with DFT (VIC-DFT). Figure 5 The middle section shows a schematic diagram of the target detection results using the CPC-NUDFT sensing method based on physically coprime subcarriers combined with non-uniform DFT (NUDFT), and... Figure 5 The rightmost part is a schematic diagram of the target detection results based on UNC using the DFT method (UNC-DFT).

[0102] In the simulation, the target vehicle is considered to have a length of 4.704m, a width of 1.810m, and a height of 1.454m. The number of reflection points N of the target vehicle is... t =16. The distances between the two vehicles are 42.6m and 132.8m, and their speeds are 30km / h and 60km / h, respectively. The noise-to-speech ratio is set to 20dB, and the signal-to-noise ratio is set to 30dB. Figure 5 It can be seen that the proposed VIC-DFT algorithm outperforms CPC-NUDFT in target detection results and can achieve target detection results close to those of UNC-DFT.

[0103] Figure 6 This is a comparative schematic diagram of the distance dimension cross-section of the distance-speed two-dimensional matrix of multiple vehicles at the same speed, obtained by different methods applicable to the technical solution of this embodiment of the invention. Figure 6 The leftmost part is the distance dimension cross-section obtained based on the VIC-DFT method. Figure 6 The middle section is a distance-dimensional cross-section obtained based on the CPC-NUDFT method. Figure 6 The rightmost part is the distance dimension cross-section obtained based on the UNC-DFT method.

[0104] In the simulation, seven targets were modeled as point targets, all with a speed of 50 km / h, a SNR of 30 dB, a CNR of 40 dB, and distances of 20 m, 40 m, 60 m, 80 m, 100 m, 120 m, and 140 m. Figure 6 As can be seen, although the VIC-DFT method proposed in the various embodiments of this invention performs worse than the UNC-DFT method, it has far fewer false peaks than the CPC-NUDFT method and can distinguish the distances of five targets. This indicates that as the CNR increases, the high sidelobes of the proposed VIC method will affect the multi-target detection performance.

[0105] It should be reiterated that the embodiments of this invention first design an OFDM sensing signal waveform based on coprime subcarrier arrangement in the 5G NR vehicle detection scenario to reduce the frequency resources occupied by the sensing integrated system. Then, based on the designed coprime subcarrier OFDM waveform, a target detection method is proposed: first, an echo signal model of coprime subcarriers is established; then, the echo signal of equivalent subcarriers is constructed; finally, a two-dimensional Fourier transform is performed on the echo signal of equivalent subcarriers to achieve target detection. This algorithm mainly utilizes the coprime sparsity characteristic to design an OFDM subcarrier sparse sensing signal waveform that satisfies the bandwidth constraints of 5G NR to solve the problem of scarce frequency resources. At the same time, it utilizes the characteristic that coprime can increase the degrees of freedom to construct the echo signal of equivalent subcarriers to avoid the performance degradation caused by the reduction of sensing overhead.

[0106] The technical solutions of the various embodiments of the present invention can be applied to the fields of 5G NR and next-generation radar communication integration to reduce the problem of spectrum resource scarcity in integrated sensing systems and obtain near-uniform sensing performance.

[0107] Example 2

[0108] Figure 7 This is a schematic diagram of a target detection device based on coprime OFDM subcarrier pulse sensing waveform provided in Embodiment 3 of the present invention. Figure 7 As shown, the device includes: a coprime subcarrier determination module 710, a coprime subcarrier waveform construction module 720, and an echo signal processing module 730, wherein:

[0109] The coprime subcarrier determination module 710 is used to determine the number of coprime factor pairs based on the communication parameters in the 5G-NR integrated sensing scenario, and to determine the coprime OFDM subcarrier index set used in the sensing scenario based on the number of coprime factor pairs.

[0110] The coprime subcarrier waveform construction module 720 is used to establish a baseband signal model of the coprime OFDM subcarrier pulse sensing waveform based on the coprime OFDM subcarrier index set, and after generating a coprime OFDM subcarrier pulse sensing baseband signal waveform that matches the baseband signal model, radiate the radio frequency signal of the coprime OFDM subcarrier pulse sensing baseband signal waveform to the surrounding environment.

[0111] The echo signal processing module 730 is used to process the echo signal based on the baseband echo signal model and the equivalent subcarrier echo signal model of the coprime OFDM subcarrier pulse sensing waveform constructed according to the vehicle target scene, and to obtain a time delay-Doppler two-dimensional matrix for target detection.

[0112] In this time-delay-Doppler two-dimensional matrix, each matrix element is used to describe the echo signal power value under a set time delay and a set Doppler frequency.

[0113] The technical solution of this invention constructs a low-overhead coprime OFDM subcarrier pulse sensing waveform and uses this coprime OFDM subcarrier pulse sensing waveform as the constructed radio frequency signal for target detection. Based on the vehicle target scenario, the baseband echo signal model and the equivalent subcarrier echo signal model of the constructed coprime OFDM subcarrier pulse sensing waveform are used to perform digital signal processing on the echo signal, resulting in a delay-Doppler two-dimensional matrix implementation method for target detection. This effectively alleviates the problem of spectrum resource scarcity and the discontinuous distribution of available subcarriers caused by large-scale user scenarios. It achieves sensing performance close to that achieved when using continuous carriers, while greatly satisfying bandwidth constraints and using the lowest possible spectrum resource overhead for sensing.

[0114] Based on the above embodiments, the coprime subcarrier determination module 710 can be specifically used for:

[0115] Based on the OFDM signal bandwidth and subcarrier spacing in the 5G-NR integrated sensing scenario, calculate the total number of subcarriers N. s ;

[0116] According to the formula: {(M,N)|(2M-1)N≤N s Given the pair of coprime factors M and N, where (M,N)=1}, determine the number of coprime factors M and N.

[0117] Where (M,N)=1 means that the greatest common divisor between M and N is 1.

[0118] Based on the above embodiments, the coprime subcarrier determination module 710 can be further specifically used for:

[0119] According to the formula: Determine the coprime OFDM subcarrier index set used in the sensing scenario

[0120] Based on the above embodiments, the coprime subcarrier waveform construction module 720 can be specifically used for:

[0121] According to the formula:

[0122] Constructing a baseband signal model s for coprime OFDM subcarrier pulse sensing waveform cop (t);

[0123] Where, N u N represents the number of pulses within a frame. cop c represents the number of coprime OFDM subcarriers in the coprime OFDM subcarrier index set. k,u p represents the modulation symbol of the k-th subcarrier and the u-th pulse. k This represents the index number of the k-th subcarrier in the coprime OFDM subcarrier index set, where Δf is the subcarrier spacing, and T... r The pulse repetition period is represented by T, which is the duration of one OFDM symbol. rect(·) represents a rectangular pulse.

[0124] Based on the above embodiments, the echo signal processing module 730 can be specifically used for:

[0125] In the vehicle target scenario, by modeling the moving vehicle as a multi-scattering point model, the baseband echo signal model of the coprime OFDM subcarrier pulse sensing waveform is constructed as follows:

[0126]

[0127] Where Q represents the number of vehicle targets, N t β represents the number of reflection points of the target vehicle. q,i This represents the backward complex amplitude of the i-th reflection point in the q-th vehicle. R represents the delay of the echo from the i-th reflection point in the q-th vehicle. i Let be the distance from the i-th reflection point to the signal source; v represents the Doppler frequency of the echo from the i-th target in the q-th vehicle. q,i Let λ be the velocity of the i-th reflection point in the q-th vehicle, λ be the wavelength of the electromagnetic wave, c be the propagation speed of the electromagnetic wave, and w(t) be the ground clutter and receiver thermal noise components.

[0128] Based on the baseband echo signal model of the coprime OFDM subcarrier pulse sensing waveform, the echo signal is sequentially processed by cyclic prefix removal, subcarrier separation, and modulation symbol removal, and then processed according to the sampling interval. The processed baseband echo signal is sampled to obtain the echo matrix Y of the physically coprime OFDM subcarrier pulse sensing signal. cop ;

[0129] Among them, the baseband echo signal (Y) of the u-th pulse and the k-th subcarrier cop ) u,k Represented as:

[0130]

[0131] Among them, Y cop N represents u ×N cop The echo matrix of the physically coprime OFDM subcarrier pulse sensing signal, (W1) u,k This represents the baseband ground clutter and receiver thermal noise components of the u-th pulse and the k-th subcarrier obtained after w(t) has undergone cyclic prefix removal, subcarrier separation, modulation symbol removal, and time-domain sampling.

[0132] According to the formula: Calculate the difference between the index numbers;

[0133] Remove the difference set The duplicate values ​​are identified, and after sorting each difference set element in ascending order, the index number of each equivalent subcarrier is obtained.

[0134] For matrix y cop Each row of elements y cop (m,:), m=1,…,N u Perform the following operations:

[0135] Among them, Y cop (m,:), m=1,…,N u , representing matrix Y cop The element in the m-th row;

[0136] According to the equivalent subcarrier index number With R cop,m Based on the correspondence of the positions of the elements, the equivalent subcarrier index number is selected. The corresponding elements form the echo signal of the equivalent subcarrier pulse sensing, and finally obtain The echo matrix Y of the equivalent subcarrier sensing pulse v ;

[0137] Wherein, the echo matrix Y v The signal of the u-th pulse and the l-th equivalent subcarrier is represented as follows:

[0138]

[0139] Among them, (Y) v ) u,l Y represents the echo signal of the sensing waveform of the u-th pulse and the l-th equivalent subcarrier pulse. v express The echo matrix of the equivalent subcarrier pulse sensing waveform, σ q,i =|β q,i | 2 This represents the power of the i-th reflection point in the q-th vehicle. W1 represents the index number of the l-th equivalent subcarrier, and W2 represents the equivalent ground clutter and receiver thermal noise components.

[0140] According to the echo matrix Y of the equivalent subcarrier sensing pulse v and the index number of each equivalent subcarrier. The time-delay-Doppler two-dimensional matrix used for target detection is obtained.

[0141] Based on the above embodiments, the coprime subcarrier waveform construction module 720 can be further specifically used for:

[0142] Based on the index number of each equivalent subcarrier Determine the number of longest consecutive subcarriers;

[0143] Based on the number of longest consecutive subcarriers, in the echo matrix Y of the equivalent subcarrier sensing pulse... v Extracting the local echo matrix of the equivalent subcarrier sensing pulse.

[0144] First, the local echo matrix of the equivalent subcarrier sensing pulse is analyzed. After performing IDFT on each row, the delay dimension matrix is ​​obtained;

[0145] Then, perform a DFT on each column of the time delay dimension matrix to obtain the time delay-Doppler two-dimensional matrix.

[0146] Based on the above embodiments, it may further include: a target detection result determination module, used for:

[0147] After obtaining the time delay-Doppler two-dimensional matrix for target detection, the time delay dimension information in the time delay-Doppler two-dimensional matrix is ​​converted into range dimension information, and the Doppler frequency dimension information in the time delay-Doppler two-dimensional matrix is ​​converted into velocity dimension information to obtain the range-velocity two-dimensional matrix.

[0148] The maximum value matrix element in the distance-velocity two-dimensional matrix is ​​obtained by traversing the matrix, and the target distance and target velocity corresponding to the maximum value matrix element are determined as the target detection result.

[0149] The target detection device based on coprime OFDM subcarrier pulse sensing waveform provided in the embodiments of the present invention can execute the target detection method based on coprime OFDM subcarrier pulse sensing waveform provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the method.

[0150] Example 3

[0151] Figure 8 A schematic diagram of an electronic device 10 that can be used to implement embodiments of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein. In various embodiments of the invention, the electronic device primarily refers to a single-station OFDM pulse radar system device for implementing target detection.

[0152] like Figure 8 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 may also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0153] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0154] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as performing a target detection method based on coprime OFDM subcarrier pulse sensing waveforms as described in any embodiment of the present invention.

[0155] That is, based on the communication parameters in the 5G-NR sensing integration scenario, determine the number of coprime factor pairs, and based on the number of coprime factor pairs, determine the coprime OFDM subcarrier index set used in the sensing scenario;

[0156] Based on the coprime OFDM subcarrier index set, a baseband signal model of the coprime OFDM subcarrier pulse sensing waveform is established. After generating a coprime OFDM subcarrier pulse sensing baseband signal waveform that matches the baseband signal model, the radio frequency signal of the coprime OFDM subcarrier pulse sensing baseband signal waveform is radiated to the surrounding environment.

[0157] Based on the vehicle target scenario, a baseband echo signal model and an equivalent subcarrier echo signal model of the coprime OFDM subcarrier pulse sensing waveform are constructed. The echo signal is processed to obtain a time delay-Doppler two-dimensional matrix for target detection.

[0158] In this time-delay-Doppler two-dimensional matrix, each matrix element is used to describe the echo signal power value under a set time delay and a set Doppler frequency.

[0159] In some embodiments, the target detection method based on coprime OFDM subcarrier pulse sensing waveforms as described in any embodiment of the present invention can be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of method 888 described above can be performed. Alternatively, in other embodiments, processor 11 can be configured by any other suitable means (e.g., by means of firmware) to perform the target detection method based on coprime OFDM subcarrier pulse sensing waveforms as described in any embodiment of the present invention.

[0160] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0161] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0162] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0163] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0164] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0165] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0166] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0167] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A target detection method based on coprime OFDM subcarrier pulse sensing waveform, characterized in that, include: Based on the communication parameters in the 5G-NR integrated sensing scenario, determine the number of coprime factor pairs, and based on the number of coprime factor pairs, determine the coprime orthogonal frequency division multiplexing (OFDM) subcarrier index set used in the sensing scenario; Based on the coprime OFDM subcarrier index set, a baseband signal model of the coprime OFDM subcarrier pulse sensing waveform is established. After generating a coprime OFDM subcarrier pulse sensing baseband signal waveform that matches the baseband signal model, the radio frequency signal of the coprime OFDM subcarrier pulse sensing baseband signal waveform is radiated to the surrounding environment. Based on the vehicle target scenario, a baseband echo signal model and an equivalent subcarrier echo signal model of the coprime OFDM subcarrier pulse sensing waveform are constructed. The echo signal is processed to obtain a time delay-Doppler two-dimensional matrix for target detection. In this context, each matrix element in the time-delay-Doppler two-dimensional matrix is ​​used to describe the echo signal power value under a set time delay and a set Doppler frequency.

2. The method according to claim 1, characterized in that, Based on the communication parameters in the 5G-NR integrated sensing scenario, determine the number of coprime factor pairs, including: Based on the OFDM signal bandwidth and subcarrier spacing in the 5G-NR integrated sensing scenario, calculate the total number of subcarriers. ; According to the formula: Determine the number of coprime factor pairs M and N ; in, represent M and N The greatest common divisor between them is 1.

3. The method according to claim 2, characterized in that, Based on the coprime factor pairs, determine the coprime OFDM subcarrier index set used in the sensing scenario, including: According to the formula: Determine the coprime OFDM subcarrier index set used in the sensing scenario. .

4. The method according to claim 1, characterized in that, Based on the coprime OFDM subcarrier index set, a baseband signal model for the coprime OFDM subcarrier pulse sensing waveform is established, including: According to the formula: Constructing a baseband signal model for coprime OFDM subcarrier pulse sensing waveforms ; in, This represents the number of pulses within a frame. This indicates the number of coprime OFDM subcarriers in the coprime OFDM subcarrier index set. Indicates the first The subcarrier, the The modulation symbol of each pulse, Indicates the first coprime OFDM subcarrier in the index set The index number of each subcarrier, For subcarrier spacing, Indicates the pulse repetition period. The duration of one OFDM symbol This represents a rectangular pulse.

5. The method according to claim 4, characterized in that, Based on the vehicle target scenario, a baseband echo signal model and an equivalent subcarrier echo signal model of the coprime OFDM subcarrier pulse sensing waveform are constructed. The echo signals are processed to obtain a time-delay-Doppler two-dimensional matrix for target detection, including: In the vehicle target scenario, by modeling the moving vehicle as a multi-scattering point model, the baseband echo signal model of the coprime OFDM subcarrier pulse sensing waveform is constructed as follows: in, Q Indicates the number of vehicle targets. The number of reflection points of the target vehicle. Indicates the first The first in the car The reverse complex amplitude of each reflection point Indicates the first The first in the car The delay of the echo at each reflection point, For the first The distance of each reflection point from the signal source; Indicates the first The first in the car The Doppler frequency of the target echo For the first The first in the car The velocity of each reflection point The wavelength of electromagnetic waves, Indicates the speed of electromagnetic wave propagation. This represents ground clutter and receiver thermal noise components; Based on the baseband echo signal model of the coprime OFDM subcarrier pulse sensing waveform, the echo signal is sequentially processed by cyclic prefix removal, subcarrier separation, and modulation symbol removal, and then processed according to the sampling interval. The processed baseband echo signal is sampled to obtain the echo matrix of the physically coprime OFDM subcarrier pulse sensing signal. ;in, This represents the total number of subcarriers. Among them, the The pulse, the first Baseband echo signal of each subcarrier Represented as: in, express The echo matrix of physically coprime OFDM subcarrier pulse sensing signals express The first subcarrier obtained after sequential processing including cyclic prefix removal, subcarrier separation, modulation symbol removal, and time-domain sampling is... The pulse, the first Baseband ground clutter and receiver thermal noise components of each subcarrier; According to the formula: The difference set of index numbers is calculated; wherein, the For coprime OFDM subcarrier index sets; Remove the difference set The duplicate values ​​are identified, and after sorting each difference set element in ascending order, the index number of each equivalent subcarrier is obtained. , ; For matrix Each row of elements Perform the following operations: ; in, , representing a matrix No. row element; According to the equivalent subcarrier index number and Based on the correspondence of the positions of the elements, the equivalent subcarrier index number is selected. The corresponding elements form the echo signal of the equivalent subcarrier pulse sensing, and finally obtain Echo matrix of equivalent subcarrier sensing pulse ; Among them, echo matrix The Middle The pulse, the first The signal of each equivalent subcarrier is represented as follows: in, Indicates the first The pulse, the first The echo signal of the sensing waveform of an equivalent subcarrier pulse. express The echo matrix of the equivalent subcarrier pulse sensing waveform. Indicates the first The first in the car The power of each reflection point Indicates the first The index number of each equivalent subcarrier, These are equivalent ground clutter and receiver thermal noise components; Based on the echo matrix of the equivalent subcarrier sensing pulse and the index number of each equivalent subcarrier. This yields a time-delay-Doppler two-dimensional matrix for target detection.

6. The method according to claim 5, characterized in that, Based on the echo matrix of the equivalent subcarrier sensing pulse and the index number of each equivalent subcarrier. The time-delay-Doppler two-dimensional matrix used for target detection is obtained, including: Based on the index number of each equivalent subcarrier Determine the number of longest consecutive subcarriers; Based on the number of longest consecutive subcarriers, in the echo matrix of the equivalent subcarrier sensing pulse... Extracting the local echo matrix of the equivalent subcarrier sensing pulse. ; First, the local echo matrix of the equivalent subcarrier sensing pulse is analyzed. After performing IDFT on each row, the time delay dimension matrix is ​​obtained; Then, perform a DFT on each column of the time delay dimension matrix to obtain the time delay-Doppler two-dimensional matrix.

7. The method according to any one of claims 1-6, characterized in that, After obtaining the time-delay-Doppler two-dimensional matrix used for target detection, the following is also included: After converting the time delay dimension information in the time delay-Doppler two-dimensional matrix into distance dimension information, and converting the Doppler frequency dimension information in the time delay-Doppler two-dimensional matrix into velocity dimension information, a distance-velocity two-dimensional matrix is ​​obtained. The maximum value matrix element in the distance-velocity two-dimensional matrix is ​​obtained by traversing the matrix, and the target distance and target velocity corresponding to the maximum value matrix element are determined as the target detection result.

8. A target detection device based on coprime OFDM subcarrier pulse sensing waveform, characterized in that, include: The coprime subcarrier determination module is used to determine the number of coprime factor pairs based on the communication parameters in the 5G-NR integrated sensing scenario, and to determine the coprime orthogonal frequency division multiplexing (OFDM) subcarrier index set used in the sensing scenario based on the number of coprime factor pairs. The coprime subcarrier waveform construction module is used to establish a baseband signal model of the coprime OFDM subcarrier pulse sensing waveform based on the coprime OFDM subcarrier index set, and after generating a coprime OFDM subcarrier pulse sensing baseband signal waveform that matches the baseband signal model, radiate the radio frequency signal of the coprime OFDM subcarrier pulse sensing baseband signal waveform to the surrounding environment. The echo signal processing module is used to process the echo signal based on the baseband echo signal model and the equivalent subcarrier echo signal model of the coprime OFDM subcarrier pulse sensing waveform constructed according to the vehicle target scene, and to obtain the time delay-Doppler two-dimensional matrix for target detection. In this context, each matrix element in the time-delay-Doppler two-dimensional matrix is ​​used to describe the echo signal power value under a set time delay and a set Doppler frequency.

9. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the target detection method based on coprime OFDM subcarrier pulse sensing waveform as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause a processor to execute the target detection method based on coprime OFDM subcarrier pulse sensing waveform as described in any one of claims 1-7.

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