Target echo detection method of multi-carrier underwater acoustic communication perception integrated system

Abstract

The invention relates to an echo detection method and device, equipment, a storage medium and a program product. The method comprises the steps that a to-be-detected signal is acquired in a preset time window, the to-be-detected signal comprises a plurality of signals corresponding to a plurality of signal transmission paths, and the Doppler frequency shift type comprises that the frequency shift of each signal component is consistent or the frequency shift of each signal component is inconsistent, so that the Doppler frequency shift of each signal component needs to be detected according to the to-be-detected signal; and determining the Doppler frequency shift type of the to-be-detected signal, and performing echo detection on the to-be-detected signal according to the Doppler frequency shift type to determine whether the to-be-detected signal comprises an echo signal. By adopting the method, the accuracy of echo detection can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of integrated underwater acoustic communication and perception, and in particular to a target echo detection method for a multi-carrier integrated underwater acoustic communication and perception system. Background Art

[0002] With the development of communication technology, integrated communication and perception technology has been widely used. For example, the implementation of integrated communication and perception technology underwater can complete tasks such as target detection, tracking, identification and information sharing, and echo detection is a common perception method.

[0003] Traditional echo detection methods usually use a matched filter to filter the received signal and select the signal corresponding to the signal transmission path with the strongest signal for echo detection.

[0004] However, the above echo detection method has the problem of inaccurate detection. Summary of the Invention

[0005] Based on this, it is necessary to provide an echo detection method, device, equipment, storage medium and program product that can improve the accuracy of echo detection in response to the above technical problems.

[0006] In a first aspect, the present application provides an echo detection method, comprising:

[0007] Acquire a signal to be detected in a preset time window, where the signal to be detected includes multiple signals corresponding to multiple signal transmission paths;

[0008] Determining a Doppler frequency shift type of the signal to be detected according to the signal to be detected, where the Doppler frequency shift type includes: a consistent frequency shift of each signal component or an inconsistent frequency shift of each signal component;

[0009] According to the Doppler frequency shift type, echo detection is performed on the signal to be detected to determine whether the signal to be detected includes an echo signal.

[0010] In one embodiment, performing echo detection on a signal to be detected according to a Doppler shift type includes:

[0011] In the case where the Doppler shift type is that the frequency shift of each signal component is consistent, determining a first Doppler shift value corresponding to each signal component according to the signal to be detected, and the first Doppler shift value corresponding to each signal component is the same;

[0012] Echo detection is performed on the signal to be detected according to the signal to be detected and the first Doppler frequency shift values corresponding to each signal component.

[0013] In one embodiment, performing echo detection on the signal to be detected according to the signal to be detected and the first Doppler frequency shift values corresponding to each signal component includes:

[0014] Determining, based on the signal to be detected and each first Doppler frequency shift value, a first probability density and a second probability density corresponding to the signal to be detected, the first probability density being used to characterize the probability distribution of the presence of an echo signal in the signal to be detected, and the second probability density being used to characterize the probability distribution of the absence of an echo signal in the signal to be detected;

[0015] Echo detection is performed on the signal to be detected according to a probability density ratio of the first probability density and the second probability density.

[0016] In one embodiment, performing echo detection on the signal to be detected according to the probability density ratio of the first probability density and the second probability density includes:

[0017] When the probability density ratio is greater than or equal to a first ratio threshold, determining that an echo signal exists in the signal to be detected;

[0018] When the probability density ratio is less than the first ratio threshold, it is determined that no echo signal exists in the signal to be detected.

[0019] In one embodiment, determining the first Doppler frequency shift value corresponding to each signal component according to the signal to be detected includes:

[0020] Determining, according to different candidate Doppler frequency shift values, a plurality of estimated signals corresponding to each candidate Doppler frequency shift value;

[0021] Obtaining a signal difference between the signal to be detected and each estimated signal;

[0022] The candidate Doppler frequency shift value corresponding to the estimated signal corresponding to the minimum signal difference is used as the first Doppler frequency shift value.

[0023] In one embodiment, performing echo detection on a signal to be detected according to a Doppler shift type includes:

[0024] In a case where the Doppler frequency shift type is that the frequency shifts of the signal components are inconsistent, determining at least one valid path from the signal transmission paths according to the signal components;

[0025] Echo detection is performed on the signal to be detected according to the multiple valid signals corresponding to each valid path.

[0026] In one embodiment, performing echo detection on the signal to be detected based on the multiple valid signals corresponding to each valid path includes:

[0027] Acquire, according to each valid signal, a second Doppler frequency shift value corresponding to each valid signal, wherein the second Doppler frequency shift value corresponding to each valid signal is different;

[0028] Determining distance data corresponding to each valid signal according to each valid signal and each second Doppler frequency shift value, where the distance data includes a first amplitude value, and the first amplitude value is used to represent the maximum radiation intensity of the valid signal;

[0029] According to each distance data, echo detection is performed on the signal to be detected.

[0030] In one embodiment, performing echo detection on the signal to be detected according to each distance data includes:

[0031] Adding the first amplitude values corresponding to the valid signals to obtain an amplitude sum value;

[0032] If the amplitude value and the value are greater than or equal to the preset value threshold, it is determined that the signal to be detected has an echo signal;

[0033] If the amplitude value and the value are less than the preset value threshold, it is determined that there is no echo signal in the signal to be detected.

[0034] In one embodiment, the distance data further includes amplitude delay, and performing echo detection on the signal to be detected based on each distance data includes:

[0035] Determine the first energy value corresponding to each valid signal according to the amplitude value, amplitude delay, and second Doppler frequency shift value corresponding to each valid signal, and obtain the energy value and value of each first energy value;

[0036] Determining a second energy value corresponding to the signal to be detected according to the signal to be detected;

[0037] If the energy ratio of the energy value sum to the second energy value is greater than or equal to the second ratio threshold, it is determined that an echo signal exists in the signal to be detected;

[0038] If the energy ratio of the energy value sum to the second energy value is less than the second ratio threshold, it is determined that there is no echo signal in the signal to be detected.

[0039] In one embodiment, determining at least one valid path from each signal transmission path according to each signal component includes:

[0040] Determining, according to each signal component, a second amplitude value corresponding to each signal component;

[0041] The signal transmission path corresponding to the signal whose second amplitude value is greater than the preset amplitude value threshold is used as a valid path.

[0042] In a second aspect, the present application further provides an echo detection device, comprising:

[0043] An acquisition module, configured to acquire a signal to be detected in a preset time window, wherein the signal to be detected includes a plurality of signals corresponding to a plurality of signal transmission paths;

[0044] a determination module, configured to determine a Doppler frequency shift type of the signal to be detected based on the signal to be detected, where the Doppler frequency shift type includes: a consistent frequency shift of each signal component or an inconsistent frequency shift of each signal component;

[0045] The echo detection module is used to perform echo detection on the signal to be detected according to the Doppler frequency shift type to determine whether the signal to be detected includes an echo signal.

[0046] In a third aspect, an embodiment of the present application provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method of the first aspect described above when executing the computer program.

[0047] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of the method of the first aspect described above when the computer program is executed by a processor.

[0048] In a fifth aspect, the present application further provides a computer program product, comprising a computer program, which, when executed by a processor, implements the steps of the method in the first aspect.

[0049] The above-described echo detection method, apparatus, device, storage medium, and program product acquire a signal to be detected within a preset time window. Because the signal to be detected includes multiple signals corresponding to multiple signal transmission paths, and the Doppler shift type includes either consistent frequency shifts for each signal component or inconsistent frequency shifts for each signal component, it is necessary to determine the Doppler shift type of the signal to be detected based on the signal to be detected, and then perform echo detection on the signal to be detected based on the Doppler shift type to determine whether the signal to be detected includes an echo signal. Traditional echo detection methods only perform echo detection on the signal transmission path with the strongest signal, failing to consider the diversity of signal transmission paths in actual application scenarios. This carries the risk of missed detections and does not consider the impact of Doppler interference on the signal during detection, resulting in low echo detection accuracy. The echo detection method, apparatus, device, storage medium, and program product provided herein perform echo detection on the signal to be detected, including multiple signal transmission paths, based on different Doppler shift types, thereby improving echo detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0051] Figure 1 A diagram showing an application environment of an echo detection method in one embodiment;

[0052] Figure 2 1 is a flow chart of an echo detection method according to an embodiment;

[0053] Figure 3 is a distance profile between the echo detection device and the target corresponding to the signals to be detected at different Doppler frequency shifts in another embodiment;

[0054] Figure 4 is a schematic diagram of channel responses under different Doppler shift types in another embodiment;

[0055] Figure 5 is a schematic flow chart of step 203 in another embodiment;

[0056] Figure 6 A graph showing the detection effect of the echo detection method provided in the embodiment of the present application and the detection effect of the traditional echo detection method in another embodiment when the Doppler shift type is a consistent frequency shift of each signal component;

[0057] Figure 7 A graph showing the detection effect of the echo detection method provided by the embodiment of the present application and the detection effect of the traditional echo detection method under different false alarm probabilities in another embodiment;

[0058] Figure 8 is a schematic flow chart of step 203 in another embodiment;

[0059] Figure 9 is a flow chart of step 802 in another embodiment;

[0060] Figure 10 FIG2 is a diagram showing the effect of performing echo detection based on energy value compared with performing echo detection based on amplitude and value in another embodiment when the Doppler shift type is inconsistent frequency shifts of various signal components;

[0061] Figure 11 2 is a detection probability diagram of two different implementations when the number of valid signals is the same in another embodiment;

[0062] Figure 12 1 is a detection probability diagram of two different implementations with the same number of subcarriers in another embodiment;

[0063] Figure 13 2 is a detection probability diagram of two different implementations with the same subcarrier spacing in another embodiment;

[0064] Figure 14is a structural block diagram of an echo detection device in one embodiment;

[0065] Figure 15 FIG. 1 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0066] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0067] With the increasing development of marine resources and marine scientific research, the demand for marine information technology is also increasing, especially in underwater monitoring and data collection. The underwater Internet of Things, consisting of various platforms and multiple types of sensors, will play a vital role in these areas. The rapid development of electronic information systems has placed higher demands on the intelligence and integration of payloads onboard underwater platforms to enable them to perform tasks in complex marine environments. Underwater acoustic communication and perception technologies are key technologies that enable underwater platforms to achieve target perception, tracking, identification, and information sharing. However, the current independent research and use of communication and perception sonar equipment not only leads to severe mutual interference but also reduces underwater resource utilization and work efficiency. To address this issue, there is an urgent need to explore the organic integration of communication and perception functions to enhance the overall effectiveness of underwater information systems.

[0068] Integrated sensing and communication (ISAC) technology is a highly promising means of information transmission and acquisition in future ocean information networks. The key concept of underwater acoustic ISAC is based on the sharing of hardware and software resources and transmit waveforms between the dry and wet ends. Based on this, resource allocation and signal processing methods are designed to achieve simultaneous and co-frequency communication and perception. Multicarrier technology is a commonly used, efficient, and reliable communication technique. Orthogonal frequency division multiplexing (OFDM), a special multicarrier technique, has been adopted in many communication standards and radar systems due to its efficient system implementation, high spectral efficiency, and robustness to inter-symbol interference. It is also a key technology widely used in ISAC systems. Unlike traditional OFDM communication and radar systems, OFDM-based underwater acoustic ISAC systems must simultaneously address information transmission and target perception performance. While existing communication processing algorithms can be directly or slightly modified for ISAC system communication information recovery, target echo detection, which is affected by random information and complex acoustic channels, remains a key issue that multicarrier underwater acoustic ISAC systems must address.

[0069] Echo signal detection is the basis and prerequisite for target parameter estimation. It can be completed through the perception receiver carried on the underwater ISAC platform. Through echo signal detection, it is possible to detect whether there is an echo signal in the received signal, thereby determining whether the target exists. Subsequently, the target's speed, distance, direction and other parameters can be effectively estimated based on the echo signal, thereby completing the detection of the target.

[0070] Most existing research on multi-carrier ISAC echo detection methods focuses on terrestrial wireless channels. Due to the significant differences in the transmission channel models between land and underwater, the underwater acoustic channel has complex time-, frequency-, and space-varying characteristics and stronger background noise interference, resulting in the inability of land-related technologies to be directly applied to the underwater acoustic channel environment and even having no reference value. Traditional echo detection methods based on matched filtering only use the direct path information of the echo signal for detection. The underwater acoustic channel is a typical multipath channel and usually has significant sparse characteristics. Using only a single path will inevitably increase the probability of missed reports and have the problem of low information utilization, which limits the detection performance.

[0071] Therefore, the above echo detection method has the problem of inaccurate detection.

[0072] In view of this, embodiments of the present application provide an echo detection method, apparatus, device, storage medium, and program product for acquiring a signal to be detected within a preset time window. Because the signal to be detected includes multiple signals corresponding to multiple signal transmission paths, and the Doppler shift type includes consistent or inconsistent frequency shifts for each signal component, it is necessary to determine the Doppler shift type of the signal to be detected based on the signal to be detected, and then perform echo detection on the signal to be detected based on the Doppler shift type to determine whether the signal to be detected includes an echo signal. Conventional echo detection methods only perform echo detection on the signal transmission path with the strongest signal, failing to consider the diversity of signal transmission paths in actual application scenarios. This carries the risk of missed detections and does not consider the impact of Doppler interference on the signal during detection, resulting in low echo detection accuracy. The target echo detection method for a multi-carrier underwater acoustic communication and perception integrated system provided by the present application performs echo detection on the signal to be detected, including multiple signal transmission paths, based on different Doppler shift types, thereby improving echo detection accuracy.

[0073] The echo detection method provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown, the echo detection device can be any device equipped with an integrated communication and perception system, capable of sending signals and performing echo detection on received signals. In one possible implementation, the echo detection device can include an underwater acoustic ISAC system.

[0074] In an exemplary embodiment, Figure 2 As shown, an echo detection method is provided, which is applied to Figure 1 The echo detection device in FIG. 1 is taken as an example to illustrate the method, which includes the following steps 201 to 203. Among them:

[0075] Step 201: Acquire a signal to be detected in a preset time window.

[0076] When the echo detection device performs a target detection task, it will send out a signal, receive a signal within a preset window, and process the signal to obtain a signal to be detected for echo detection, wherein the signal to be detected includes multiple signals corresponding to multiple signal transmission paths.

[0077] The preset time window is a time period. In the embodiment of the present application, after the echo detection device sends an integrated signal for underwater acoustic communication and perception, the signal to be detected will be received within the preset time window. In a possible implementation, in an actual application scenario, there may be a situation where the target is too far away from the echo detection device. At this time, the signal to be detected with an echo signal may not be received within the preset time window. In order to avoid missed detection and improve detection efficiency, a sliding time window method can be used. For example, the preset time window is T w , then every time T s , slide the time window to the current time, for example, the time range of the preset time window is 0~T w , when time passes T s , then the preset time window is sliding, and the time range of the preset time window becomes the new T s ~T w +T s .

[0078] In a possible embodiment, the signal to be detected obtained by the echo detection device in the preset time window can be represented by the integrated signal emitted by the echo detection device and the target reflected echo signal superimposed on the environmental noise. The signal emitted by the echo detection device can be of duration T and include N c subcarrier OFDM symbol, then we can set the kth subcarrier frequency f k The expression is:

[0079] f k =f l +kΔf,k=0,…,N c -1(1)

[0080] Among them, f l is the carrier frequency, Δf is the subcarrier spacing, so the bandwidth B=N c Δf, the complex baseband signal corresponding to the mth symbol block can be expressed by the following formula.

[0081]

[0082] Among them, n∈[0,N c -1] represents a discrete time index variable, d m [k]=[d[0],d[1],…,d[N c -1]] T Represents the phase modulation symbol transmitted by the mth symbol block, which includes data and pilot symbols, that is, s m (n) is d m [k] The result obtained after inverse Fourier transform.

[0083] After up-conversion processing, the baseband signal is converted into a passband transmission signal, which can be expressed by the following formula.

[0084]

[0085] Where t∈[0,T′], T′ is the time interval for the echo detection device to transmit multi-carrier pulses, T′=T+T g , T g is the time of zero-crossing protection, g(t) represents the rectangular window function.

[0086] In an embodiment of the present application, after the echo detection device sends a signal, if there is a target in the underwater measurement area, the signal to be detected obtained by the echo detection device will include the target echo signal. However, the relative position of the target and the echo detection device is not necessarily constant. When there is relative motion between the target and the echo detection device, the frequency of the received signal to be detected and the signal sent by the echo detection device will be different. This phenomenon is called Doppler interference, and the offset frequency is called Doppler shift.

[0087] It is understandable that the underwater acoustic channel has typical multipath fading, Doppler effect and sparse structure, and can be constructed as a parameterized channel model. Assuming that the underwater acoustic channel has P main discrete arrival paths, the underwater acoustic channel impulse response can be defined as:

[0088]

[0089] Among them, A p (t) and τ p (t) represent the amplitude and delay of the pth signal path, and τ p (t) = τ p -λ p (t)t,λ p is the Doppler scale factor of the p-th path.

[0090] Typically, the channel amplitude and Doppler are constant within the duration of a symbol block, and the channel impulse response can be expressed by the following formula:

[0091]

[0092] The signal emitted by the echo detection device reaches the receiving node directly or through a reflection from the sea surface and the seabed for communication, and at the same time is reflected back to the echo detection device by the target for echo detection. Therefore, the echo signal It can be expressed as:

[0093]

[0094] in, is the received environmental noise, which can be modeled as zero-mean additive Gaussian white noise. Since the target is stationary, the Doppler scale factor can be estimated based on the moving speed of the integrated node. It is used for coarse Doppler compensation of echo signals, which can be expressed by the following formula:

[0095]

[0096] in, is the frequency-independent carrier frequency offset (CFO) corresponding to the p-th signal path after coarse Doppler compensation, is the noise after Doppler compensation. is the distance profile between the echo detection device and the target corresponding to the signal to be detected with different Doppler frequency shifts. The distance profile can be obtained by transferring the signal to be detected to the frequency domain, eliminating random information, and performing inverse discrete Fourier transform. Figure 3 It can be seen that the higher the Doppler shift value, the higher the sidelobe level, the lower the peak ratio of the main lobe and sidelobe of the range profile, and the lower the accuracy of echo detection. Therefore, it is necessary to introduce Doppler shift when sampling the received signal to facilitate the subsequent elimination of the influence of Doppler shift on the signal to be detected.

[0097] Optionally, the echo detection device samples the signal according to a preset time period. Optionally, the sampling times are preset. The echo detection device can determine the time of sampling the signal according to the preset sampling times and sample the signal at the time of sampling the signal. For example, the duration of the preset time window is T w , and the preset number of sampling points is N w times, then the echo detection device can determine the time interval t = nT w / N w Sampled signal. To simplify the representation, the subscript m is omitted. At this time, the time domain baseband complex signal can be expressed as:

[0098]

[0099] Where w[n] is the baseband discrete noise after sampling.

[0100] Based on the above content, the signal to be detected can be expressed as a matrix vector:

[0101]

[0102] in, β p and τ p represent the amplitude coefficient, CFO, and delay of the p-th path respectively. Indicates N w ×N c A zero-filled matrix of dimension , is the discrete Fourier transform matrix, and the nth element in the qth row of the matrix is is zero-mean complex Gaussian white noise with variance B(τ p ) is the frequency domain phase shift matrix, D(β p ) is the phase rotation matrix, which is expressed by the following formulas:

[0103]

[0104] In the embodiment of the present application, in order to obtain the complete multipath information of the signal in a preset time window, an overlap-add matrix R is constructed. ola , expressed as:

[0105]

[0106] The overlap-add matrix R ola Multiply the above reconstructed signal to be detected by left The signal z to be detected for subsequent echo detection is obtained, where:

[0107] Step 202: Determine the Doppler frequency shift type of the signal to be detected according to the signal to be detected.

[0108] Since the signal to be detected includes signals corresponding to multiple signal transmission paths, the Doppler frequency shift values of these signals may be the same or different. Therefore, the Doppler frequency shift type includes consistent frequency shift of each signal component or inconsistent frequency shift of each signal component. When the frequency shift of each signal component is consistent, it indicates that the signals of each signal transmission path of the signal to be detected have consistent Doppler frequency shift values. When the frequency shift of each signal component is inconsistent, it indicates that the signals of each signal transmission path of the signal to be detected have inconsistent Doppler frequency shift values. The echo detection equipment can determine the Doppler frequency shift type of the acquired signal to be detected according to the preset Doppler frequency shift type judgment condition. The preset Doppler frequency shift type judgment condition can be set according to the empirical value.

[0109] Step 203: Perform echo detection on the signal to be detected according to the Doppler shift type to determine whether the signal to be detected includes an echo signal.

[0110] The Doppler shift type is used to characterize the type of Doppler interference that affects the signals corresponding to the various signal transmission paths included in the signal to be detected. Different Doppler shift types corresponding to the signals to be detected will affect the Doppler interference that affects each signal differently, and the echo detection method may be different. Figure 4 , is the channel response under different Doppler frequency shift types. Optionally, when the Doppler frequency shift type is that the frequency shift of each signal component is consistent, it indicates that the signals corresponding to each signal transmission path of the signal to be detected are affected by the same Doppler interference. Therefore, the echo detection device needs to determine the same Doppler frequency shift value on each signal transmission path of the signal to be detected, and then perform echo detection on the signal to be detected according to each same Doppler frequency shift value; optionally, when the Doppler frequency shift type is that the frequency shift of each signal component is inconsistent, it indicates that the signals corresponding to each signal transmission path of the signal to be detected are affected by the Doppler interference differently. The echo detection device needs to determine the different Doppler frequency shift values on the transmission path of each signal component, and then perform echo detection on the signal to be detected according to each different Doppler frequency shift value.

[0111] After the echo detection device performs echo detection on the signal to be detected, it can determine whether the signal to be detected includes the echo signal. If not, the signal to be detected will no longer be processed. If included, it can be determined that the target detection is successful. By performing subsequent analysis and processing on the signal to be detected, parameters such as the target speed, direction, and distance between the target and the echo detection device can be effectively estimated.

[0112] The above-mentioned echo detection method obtains a signal to be detected within a preset time window. Since the signal to be detected includes multiple signals corresponding to multiple signal transmission paths, and the Doppler shift type includes consistent frequency shifts for each signal component or inconsistent frequency shifts for each signal component, it is necessary to determine the Doppler shift type of the signal to be detected based on the signal to be detected, and then perform echo detection on the signal to be detected based on the Doppler shift type to determine whether the signal to be detected includes an echo signal. Traditional echo detection methods only perform echo detection on the signal transmission path with the strongest signal, failing to consider the diversity of signal transmission paths in actual application scenarios. This poses a risk of missed detections and does not consider the impact of Doppler interference on the signal during detection, resulting in low echo detection accuracy. The echo detection method, apparatus, device, storage medium, and program product provided in this application perform echo detection on a signal to be detected that includes multiple signal transmission paths based on different Doppler shift types, thereby improving the accuracy of echo detection.

[0113] In one embodiment, based on Figure 2 The embodiment shown, see Figure 5 , the embodiment of the present application relates to a process of performing echo detection on a signal to be detected according to the type of Doppler shift. Figure 5 As shown, step 203 may include Figure 5 Steps 501 and 502 are shown.

[0114] Step 501: When the Doppler frequency shift type is that the frequency shifts of the signal components are consistent, determine a first Doppler frequency shift value corresponding to each signal component according to the signal to be detected.

[0115] When the Doppler frequency shift type is that the frequency shift of each signal component is consistent, the signals corresponding to each signal transmission path of the signal to be detected are affected by the same Doppler interference, and the first Doppler frequency shift value corresponding to each signal component is the same. The echo detection device can determine the first Doppler frequency shift value corresponding to each signal component based on the signal to be detected.

[0116] Regarding the method for the echo detection device to determine the first Doppler frequency shift value, in one possible implementation, the echo detection device can determine multiple estimated signals corresponding to each candidate Doppler frequency shift value based on different candidate Doppler frequency shift values, thereby obtaining the signal difference between the signal to be detected and each estimated signal, and taking the candidate Doppler frequency shift value corresponding to the estimated signal corresponding to the minimum signal difference as the first Doppler frequency shift value.

[0117] The first Doppler frequency shift value is an unknown parameter. The echo detection device needs to estimate the first Doppler frequency shift value based on the signal to be detected. In the embodiment of the present application, the echo detection device can estimate the first Doppler frequency shift value based on the least squares estimation method.

[0118] For example, the expression of the preset estimated signal is D(β P )F H diag(d)F L h, where represents the first L columns of the discrete Fourier transform matrix F, h is the channel response, and its estimated value can be expressed as in

[0119] By substituting a plurality of different candidate Doppler frequency shift values β into the expression of the estimated signal, the estimated signal corresponding to each candidate Doppler frequency shift value can be determined.

[0120] When the candidate Doppler shift value is closer to the first Doppler shift value of each signal component of the signal to be detected, the estimated signal and the signal to be detected are closer, that is, the signal difference is smaller. The signal difference between the estimated signal and the signal to be detected is digitized using the least squares estimation method, and the expression is:

[0121]

[0122] Substituting the channel response into formula (12), the expression is:

[0123]

[0124] in,

[0125] Using formula (13), the minimum signal difference between the detection signal and each estimated signal can be determined. The estimated signal corresponding to the minimum signal difference is closest to the signal to be detected, and its corresponding candidate Doppler frequency shift value can be used as the first Doppler frequency shift value.

[0126] Step 502: Perform echo detection on the signal to be detected according to the signal to be detected and the first Doppler frequency shift values corresponding to each signal component.

[0127] The echo detection device obtains the first Doppler frequency shift value and can perform echo detection on the signal to be detected according to the signal to be detected and the first Doppler frequency shift value. For example, the echo detection can be performed using binary hypothesis testing, or using constant false alarm detection technology.

[0128] The echo detection device performs echo detection on the signal to be detected to determine whether an echo signal exists in the signal to be detected. Optionally, a binary hypothesis model can be established with two hypotheses: one hypothesis, H0, is that the signal to be detected contains both an echo signal and noise, and the other hypothesis, H1, is that the signal to be detected contains only noise. The binary hypothesis model can be expressed as:

[0129]

[0130] Next, we can use the generalized likelihood ratio test method to make decisions on these two hypotheses and obtain the generalized likelihood ratio test formula:

[0131]

[0132] Wherein, η' is the first ratio threshold value determined according to the constant false alarm detection technology, and the numerator is the first probability density, which is used to characterize the probability distribution of the presence of the echo signal in the signal to be detected. is the second probability density, which is used to characterize the probability distribution that there is no echo signal in the signal to be detected. In the embodiment of the present application, the second probability density is used to characterize the probability distribution that only Gaussian white noise exists in the signal to be detected.

[0133] In one possible embodiment, the echo detection device can determine the first probability density and the second probability density corresponding to the signal to be detected based on the signal to be detected and each first Doppler frequency shift value, and perform echo detection on the signal to be detected based on the probability density ratio of the first probability density and the second probability density. Optionally, when the probability density ratio is greater than or equal to a first ratio threshold, it is determined that an echo signal exists in the signal to be detected. Optionally, when the probability density ratio is less than the first ratio threshold, it is determined that no echo signal exists in the signal to be detected.

[0134] In a possible implementation, for convenience of calculation, formula (12) can be further derived as follows:

[0135]

[0136] Wherein, η=lnη′.

[0137] Then, substituting the channel response h above into formula 13, the formula can be derived as follows:

[0138]

[0139] In this embodiment, when the echo detection device detects the signal to be detected, the first Doppler frequency shift value of each signal component and the information and pilot symbol can be substituted into formula (17) to determine whether there is an echo signal in the signal to be detected.

[0140] See also Figure 6 , is a curve diagram of the detection effect of the echo detection method provided by the embodiment of the present application and the detection effect of the traditional echo detection method when the Doppler frequency shift type is the same for each signal component, wherein the first Doppler frequency shift value is 2 Hz, the false alarm probability is 0.01, and the number of subcarriers N of 1 OFDM is cis 256, and the subcarrier spacing is Δf=4 Hz. It can be seen that when the signal-to-noise ratio is lower than -10 dB, the echo detection method provided in the present application has a higher detection probability.

[0141] Reference Figure 7 , which is a curve diagram of the detection effect of the echo detection method provided by the embodiment of the present application and the detection effect of the traditional echo detection method under different false alarm probabilities. The signal-to-noise ratio is fixed at -16dB, and the horizontal axis is the number of subcarriers N c Increase, the vertical axis is the detection probability, and the false alarm probabilities corresponding to cases 1, 2, and 3 are different. It can be seen that when the false alarm probability and the number of subcarriers are the same, the echo detection method provided in the embodiment of the present application has a higher detection probability and higher accuracy.

[0142] In one embodiment, based on Figure 2 The embodiment shown, see Figure 8 , the embodiment of the present application relates to a process of performing echo detection on a signal to be detected according to the type of Doppler shift. Figure 8 As shown, step 203 may include Figure 8 Steps 801 and 802 are shown.

[0143] Step 801: When the Doppler frequency shift type is that the frequency shifts of the signal components are inconsistent, determine at least one valid path from the signal transmission paths according to the signal components.

[0144] When the Doppler frequency shift type is inconsistent in the frequency shift of each signal component, it indicates that the signals corresponding to each signal transmission path of the signal to be detected are affected differently by Doppler interference. Therefore, the echo detection equipment needs to process and analyze the signals of each channel transmission path. However, the signals corresponding to each signal transmission path are different. The echo detection equipment needs to select at least one valid path from each signal transmission path, and the signal strength corresponding to the valid path can reach a certain threshold.

[0145] Regarding the method for determining the effective path, in one possible implementation, the echo detection device can determine the second amplitude value corresponding to each signal component based on each signal component, and use the signal transmission path corresponding to the signal with a second amplitude value greater than a preset amplitude value threshold as the effective path, where the second amplitude value is the amplitude coefficient of each signal component corresponding to the transmission path of each signal component.

[0146] At this time, the signal z composed of the signals corresponding to each valid path 有效 can be expressed as:

[0147]

[0148] Where i is the index of the valid signal and P is the number of valid signals.

[0149] Step 802: Perform echo detection on the signal to be detected according to the multiple valid signals corresponding to each valid path.

[0150] After determining each valid signal, the echo detection device can perform echo detection on the signal to be detected based on each valid signal. Optionally, the echo detection device can detect the energy value of each valid signal based on each valid signal, thereby determining whether the signal to be detected includes an echo signal. Optionally, the echo detection device can detect the signal strength of each valid signal based on each valid signal, thereby determining whether the signal to be detected includes an echo signal.

[0151] In one embodiment, based on Figure 8 The embodiment shown, see Figure 9 , the embodiment of the present application relates to a process of performing echo detection on a signal to be detected based on multiple valid signals corresponding to each valid path. Figure 9 As shown, step 802 may include Figure 9 Steps 901 to 903 are shown.

[0152] Step 901: Acquire a second Doppler frequency shift value corresponding to each valid signal according to each valid signal.

[0153] Among them, since the Doppler shift type is inconsistent in the frequency shift of each signal component, the second Doppler shift value corresponding to each valid signal is different. Regarding the method for obtaining the second Doppler shift value corresponding to each valid signal, it can be reconstructed by presetting the second Doppler shift value as an unknown parameter. Then, for the second Doppler shift value corresponding to the i-th valid signal The expression is:

[0154]

[0155] in, is the reconstructed echo of the i-1th valid signal.

[0156] Step 902: Determine distance data corresponding to each valid signal according to each valid signal and each second Doppler frequency shift value.

[0157] The distance data includes a first amplitude value, and the first amplitude value is used to represent the maximum radiation intensity of the effective signal.

[0158] The distance data can be obtained based on each valid signal, and the distance profile between the echo detection device and the target corresponding to each valid signal is r, and the distance profile r corresponding to the i-th valid signal is r. i can be expressed as:

[0159]

[0160] That is, perform discrete Fourier transform on the i-th effective signal, Represents the division operator.

[0161] The horizontal axis of the distance profile is the time delay corresponding to the effective signal, and the vertical axis is the radiation intensity value of the effective signal. The maximum radiation intensity value is the first amplitude value corresponding to the effective signal. The first amplitude value corresponding to the i-th effective signal is:

[0162]

[0163] in, is the amplitude delay corresponding to the first amplitude value.

[0164] Step 903: Perform echo detection on the signal to be detected according to each distance data.

[0165] In a possible implementation, the echo detection device may add the first amplitude values corresponding to the valid signals to obtain an amplitude sum value. The specific detection formula is as follows:

[0166]

[0167] Wherein, H1 is the assumption that the signal to be detected includes the echo signal, H0 is the assumption that the signal to be detected includes the echo signal, and η AAC It is a preset sum value threshold. In the embodiment of the present application, if the amplitude value and the value are greater than or equal to the preset sum value threshold, it is determined that there is an echo signal in the signal to be detected; if the amplitude value and the value are less than the preset sum value threshold, it is determined that there is no echo signal in the signal to be detected.

[0168] In another possible implementation, the echo detection device can calculate the energy value of each valid signal to perform echo detection on the signal to be detected. In this embodiment, the distance data also includes amplitude delay, and the amplitude delay is the value on the horizontal axis corresponding to the first amplitude value in the distance profile. Then, the echo detection device can determine the first energy value corresponding to each valid signal based on the amplitude value, amplitude delay and second Doppler frequency shift value corresponding to each valid signal, and obtain the energy value and value of each first energy value, and determine the second energy value corresponding to the signal to be detected based on the signal to be detected.

[0169] The greater the proportion of the energy sum value to the second energy value, the greater the probability that an echo signal exists in the signal to be detected. Therefore, the echo detection device needs to determine the energy ratio of the energy sum value to the second energy value to obtain the detection formula:

[0170]

[0171] Among them, η ERA second ratio threshold is preset. If the energy ratio of the energy value sum and the second energy value is greater than or equal to the second ratio threshold, it is determined that there is an echo signal in the signal to be detected. If the energy ratio of the energy value sum and the second energy value is less than the second ratio threshold, it is determined that there is no echo signal in the signal to be detected.

[0172] The echo detection methods of the above two embodiments are two parallel detection schemes with different detection probabilities. Figure 10 , when the Doppler shift type is inconsistent for each signal component, set the number of subcarriers N c =512, Δf = 4 Hz, and the false alarm probability is set to 0.01. It can be seen that the more valid signals are identified, the higher the detection probability and accuracy. Echo detection based on energy value has a higher detection probability and higher detection accuracy than echo detection based on amplitude and value.

[0173] See also Figure 11 , which is a detection probability diagram of two different implementation methods when the number of valid signals is the same, and the signal-to-noise ratio is fixed at -14dB. It can be seen that when the number of valid signals increases, the detection probability of echo detection based on energy value is higher than that of echo detection based on amplitude and value, and the detection accuracy is higher.

[0174] See also Figure 12 , which is the detection probability diagram of two different implementation methods with the same number of subcarriers, the false alarm rate is 0.01, the signal-to-noise ratio is fixed at -14dB, and the carrier spacing is 4Hz. It can be seen that as the number of subcarriers increases, the detection probability is higher, and the detection probability of echo detection based on energy value is higher than that of echo detection based on amplitude and value.

[0175] See also Figure 13 , which is a detection probability diagram of two different implementation methods with the same subcarrier spacing. It can be seen that as the subcarrier spacing increases, the detection probability is higher, and the detection probability of echo detection based on energy value is higher than that of echo detection based on amplitude and value.

[0176] In one embodiment, an echo detection method is provided, the method comprising the following steps:

[0177] Step a: Acquire the signal to be detected in a preset time window.

[0178] The signal to be detected includes multiple signals corresponding to multiple signal transmission paths.

[0179] Step b: determining the Doppler frequency shift type of the signal to be detected according to the signal to be detected.

[0180] The Doppler frequency shift type includes the frequency shift of each signal component being consistent or the frequency shift of each signal component being inconsistent.

[0181] Step c: when the Doppler shift type is that the frequency shift of each signal component is consistent, determining multiple estimated signals corresponding to each candidate Doppler shift value according to different candidate Doppler shift values.

[0182] Step d: obtaining the signal difference between the signal to be detected and each estimated signal.

[0183] Step e: taking the candidate Doppler frequency shift value corresponding to the estimated signal corresponding to the minimum signal difference as the first Doppler frequency shift value.

[0184] The first Doppler frequency shift values corresponding to the various signal components are the same.

[0185] Step f: determining a first probability density and a second probability density corresponding to the signal to be detected according to the signal to be detected and each first Doppler frequency shift value.

[0186] The first probability density is used to characterize the probability distribution of the presence of an echo signal for the signal to be detected, and the second probability density is used to characterize the probability distribution of the absence of an echo signal for the signal to be detected.

[0187] Step g: When the probability density ratio is greater than or equal to a first ratio threshold, determining that an echo signal exists in the signal to be detected.

[0188] Step h: When the probability density ratio is less than the first ratio threshold, it is determined that there is no echo signal in the signal to be detected.

[0189] Step i: when the Doppler frequency shift type is that the frequency shifts of the signal components are inconsistent, determining the second amplitude value corresponding to each signal component according to each signal component.

[0190] Step j: taking the signal transmission path corresponding to the signal whose second amplitude value is greater than the preset amplitude value threshold as a valid path.

[0191] Step k: acquiring, according to each valid signal, a second Doppler frequency shift value corresponding to each valid signal.

[0192] The second Doppler frequency shift values corresponding to the valid signals are different.

[0193] Step 1: Determine the distance data corresponding to each valid signal according to each valid signal and each second Doppler frequency shift value.

[0194] The distance data includes a first amplitude value, and the first amplitude value is used to represent the maximum radiation intensity of the effective signal.

[0195] Step m: add the first amplitude values corresponding to the valid signals to obtain the amplitude sum value.

[0196] Step n: If the amplitude value and the value are greater than or equal to the preset value threshold, it is determined that the signal to be detected has an echo signal.

[0197] In step o, if the amplitude value and the value are less than the preset value threshold, it is determined that there is no echo signal in the signal to be detected.

[0198] Among them, the distance data also includes amplitude delay.

[0199] Step p: determining the first energy value corresponding to each valid signal according to the amplitude value, amplitude delay and second Doppler frequency shift value corresponding to each valid signal, and obtaining the energy value and value of each first energy value.

[0200] Step q: determining a second energy value corresponding to the signal to be detected based on the signal to be detected.

[0201] In step r, if the energy ratio of the energy value sum to the second energy value is greater than or equal to a second ratio threshold, it is determined that an echo signal exists in the signal to be detected.

[0202] In step s, if the energy ratio of the energy value sum to the second energy value is less than a second ratio threshold, it is determined that there is no echo signal in the signal to be detected.

[0203] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0204] Based on the same inventive concept, embodiments of the present application further provide an echo detection device for implementing the aforementioned echo detection method. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more echo detection device embodiments provided below can be found in the above-described limitations of the echo detection method and will not be further elaborated here.

[0205] In an exemplary embodiment, Figure 14As shown, an echo detection device is provided, including: an acquisition module 1401, a determination module 1402 and an L module, wherein:

[0206] An acquisition module 1401 is configured to acquire a signal to be detected in a preset time window, where the signal to be detected includes multiple signals corresponding to multiple signal transmission paths;

[0207] a determination module 1402, configured to determine a Doppler shift type of the signal to be detected based on the signal to be detected, where the Doppler shift type includes: a consistent frequency shift of each signal component or an inconsistent frequency shift of each signal component;

[0208] The echo detection module 1403 is configured to perform echo detection on the signal to be detected according to the Doppler frequency shift type to determine whether the signal to be detected includes an echo signal.

[0209] In one embodiment, the echo detection module 1403 includes:

[0210] a first Doppler shift value determining unit, configured to determine, according to the signal to be detected, a first Doppler shift value corresponding to each of the signal components when the Doppler shift type is that the frequency shifts of the signal components are consistent, so that the first Doppler shift values corresponding to the signal components are the same;

[0211] The consistent echo detection unit is configured to perform echo detection on the signal to be detected according to the signal to be detected and the first Doppler frequency shift value corresponding to each of the signal components.

[0212] In one embodiment, the coincident echo detection unit is further configured to:

[0213] Determining, based on the signal to be detected and each of the first Doppler frequency shift values, a first probability density and a second probability density corresponding to the signal to be detected, wherein the first probability density is used to characterize the probability distribution of the presence of the echo signal in the signal to be detected, and the second probability density is used to characterize the probability distribution of the absence of the echo signal in the signal to be detected;

[0214] Echo detection is performed on the signal to be detected according to a probability density ratio of the first probability density to the second probability density.

[0215] In one embodiment, the coincident echo detection unit is further configured to:

[0216] When the probability density ratio is greater than or equal to a first ratio threshold, determining that the echo signal exists in the signal to be detected;

[0217] When the probability density ratio is less than the first ratio threshold, it is determined that the echo signal does not exist in the signal to be detected.

[0218] In one embodiment, the first Doppler frequency shift value determining unit is further configured to:

[0219] Determining, according to different candidate Doppler frequency shift values, a plurality of estimated signals corresponding to each candidate Doppler frequency shift value;

[0220] Obtaining a signal difference between the signal to be detected and each of the estimated signals;

[0221] The candidate Doppler frequency shift value corresponding to the estimated signal corresponding to the minimum signal difference is used as the first Doppler frequency shift value.

[0222] In one embodiment, the echo detection module 1403 includes:

[0223] an effective path determining unit, configured to determine at least one effective path from each of the signal transmission paths according to each of the signal components when the Doppler frequency shift type is inconsistent frequency shifts of the signal components;

[0224] The inconsistent echo detection unit is configured to perform echo detection on the signal to be detected according to a plurality of valid signals corresponding to each of the valid paths.

[0225] In one embodiment, the inconsistent echo detection unit is further configured to:

[0226] Acquire, according to each of the valid signals, a second Doppler frequency shift value corresponding to each of the valid signals, wherein the second Doppler frequency shift value corresponding to each of the valid signals is different;

[0227] Determining distance data corresponding to each of the valid signals according to each of the valid signals and each of the second Doppler frequency shift values, wherein the distance data includes a first amplitude value, and the first amplitude value is used to represent the maximum radiation intensity of the valid signal;

[0228] Perform echo detection on the signal to be detected according to each of the distance data.

[0229] In one embodiment, the inconsistent echo detection unit is further configured to:

[0230] Adding the first amplitude values corresponding to the valid signals to obtain an amplitude sum value;

[0231] If the amplitude value and value are greater than or equal to a preset sum value threshold, it is determined that an echo signal exists in the signal to be detected;

[0232] If the amplitude value and value are smaller than the preset value threshold, it is determined that there is no echo signal in the signal to be detected.

[0233] In one embodiment, the inconsistent echo detection unit is further configured to:

[0234] Determine, according to the amplitude value, the amplitude delay, and the second Doppler frequency shift value corresponding to each of the valid signals, a first energy value corresponding to each of the valid signals, and obtain an energy value and value of each of the first energy values;

[0235] determining, according to the signal to be detected, a second energy value corresponding to the signal to be detected;

[0236] If the energy ratio of the energy value sum to the second energy value is greater than or equal to a second ratio threshold, determining that an echo signal exists in the signal to be detected;

[0237] If the energy ratio of the energy value sum to the second energy value is less than a second ratio threshold, it is determined that no echo signal exists in the signal to be detected.

[0238] In one embodiment, the valid path determination unit is further configured to:

[0239] Determining, according to each of the signal components, a second amplitude value corresponding to each of the signal components;

[0240] The signal transmission path corresponding to the signal whose second amplitude value is greater than a preset amplitude value threshold is used as the valid path.

[0241] Each module in the above-mentioned echo detection device can be implemented in whole or in part through software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in the computer device in the form of software, so that the processor can call and execute the corresponding operations of each module.

[0242] In an exemplary embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as shown in FIG. Figure 15As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O) and a communication interface. The processor, the memory and the input / output interface are connected via a system bus, and the communication interface is connected to the system bus via the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store echo detection data. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, an echo detection method is implemented.

[0243] Those skilled in the art will understand that Figure 15 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0244] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the following steps are implemented:

[0245] Acquire a signal to be detected in a preset time window, wherein the signal to be detected includes multiple signals corresponding to multiple signal transmission paths;

[0246] determining, according to the signal to be detected, a Doppler shift type of the signal to be detected, the Doppler shift type including: a consistent frequency shift of each signal component or a inconsistent frequency shift of each signal component;

[0247] According to the Doppler frequency shift type, echo detection is performed on the signal to be detected to determine whether the signal to be detected includes an echo signal.

[0248] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0249] In a case where the Doppler shift type is that the frequency shifts of the signal components are consistent, determining a first Doppler shift value corresponding to each of the signal components according to the signal to be detected, the first Doppler shift value corresponding to each of the signal components being the same;

[0250] Echo detection is performed on the signal to be detected according to the signal to be detected and the first Doppler frequency shift values corresponding to the signal components.

[0251] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0252] Determining, based on the signal to be detected and each of the first Doppler frequency shift values, a first probability density and a second probability density corresponding to the signal to be detected, wherein the first probability density is used to characterize the probability distribution of the presence of the echo signal in the signal to be detected, and the second probability density is used to characterize the probability distribution of the absence of the echo signal in the signal to be detected;

[0253] Echo detection is performed on the signal to be detected according to a probability density ratio of the first probability density to the second probability density.

[0254] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0255] When the probability density ratio is greater than or equal to a first ratio threshold, determining that the echo signal exists in the signal to be detected;

[0256] When the probability density ratio is less than the first ratio threshold, it is determined that the echo signal does not exist in the signal to be detected.

[0257] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0258] Determining, according to different candidate Doppler frequency shift values, a plurality of estimated signals corresponding to each candidate Doppler frequency shift value;

[0259] Obtaining a signal difference between the signal to be detected and each of the estimated signals;

[0260] The candidate Doppler frequency shift value corresponding to the estimated signal corresponding to the minimum signal difference is used as the first Doppler frequency shift value.

[0261] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0262] When the Doppler shift type is that the frequency shifts of the signal components are inconsistent, determining at least one valid path from the signal transmission paths according to the signal components;

[0263] Echo detection is performed on the signal to be detected according to the multiple valid signals corresponding to each of the valid paths.

[0264] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0265] Acquire, according to each of the valid signals, a second Doppler frequency shift value corresponding to each of the valid signals, wherein the second Doppler frequency shift value corresponding to each of the valid signals is different;

[0266] Determining distance data corresponding to each of the valid signals according to each of the valid signals and each of the second Doppler frequency shift values, wherein the distance data includes a first amplitude value, and the first amplitude value is used to represent the maximum radiation intensity of the valid signal;

[0267] Perform echo detection on the signal to be detected according to each of the distance data.

[0268] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0269] Adding the first amplitude values corresponding to the valid signals to obtain an amplitude sum value;

[0270] If the amplitude value and value are greater than or equal to a preset sum value threshold, it is determined that an echo signal exists in the signal to be detected;

[0271] If the amplitude value and value are smaller than the preset value threshold, it is determined that there is no echo signal in the signal to be detected.

[0272] In one embodiment, the distance data further includes amplitude delay, and the processor further implements the following steps when executing the computer program:

[0273] Determine, according to the amplitude value, the amplitude delay, and the second Doppler frequency shift value corresponding to each of the valid signals, a first energy value corresponding to each of the valid signals, and obtain an energy value and value of each of the first energy values;

[0274] determining, according to the signal to be detected, a second energy value corresponding to the signal to be detected;

[0275] If the energy ratio of the energy value sum to the second energy value is greater than or equal to a second ratio threshold, determining that an echo signal exists in the signal to be detected;

[0276] If the energy ratio of the energy value sum to the second energy value is less than a second ratio threshold, it is determined that no echo signal exists in the signal to be detected.

[0277] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0278] Determining, according to each of the signal components, a second amplitude value corresponding to each of the signal components;

[0279] The signal transmission path corresponding to the signal whose second amplitude value is greater than a preset amplitude value threshold is used as the valid path.

[0280] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0281] Acquire a signal to be detected in a preset time window, wherein the signal to be detected includes multiple signals corresponding to multiple signal transmission paths;

[0282] determining, according to the signal to be detected, a Doppler shift type of the signal to be detected, the Doppler shift type including: a consistent frequency shift of each signal component or a inconsistent frequency shift of each signal component;

[0283] According to the Doppler frequency shift type, echo detection is performed on the signal to be detected to determine whether the signal to be detected includes an echo signal.

[0284] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0285] In a case where the Doppler shift type is that the frequency shifts of the signal components are consistent, determining a first Doppler shift value corresponding to each of the signal components according to the signal to be detected, the first Doppler shift value corresponding to each of the signal components being the same;

[0286] Echo detection is performed on the signal to be detected according to the signal to be detected and the first Doppler frequency shift values corresponding to the signal components.

[0287] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0288] Determining, based on the signal to be detected and each of the first Doppler frequency shift values, a first probability density and a second probability density corresponding to the signal to be detected, wherein the first probability density is used to characterize the probability distribution of the presence of the echo signal in the signal to be detected, and the second probability density is used to characterize the probability distribution of the absence of the echo signal in the signal to be detected;

[0289] Echo detection is performed on the signal to be detected according to a probability density ratio of the first probability density to the second probability density.

[0290] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0291] When the probability density ratio is greater than or equal to a first ratio threshold, determining that the echo signal exists in the signal to be detected;

[0292] When the probability density ratio is less than the first ratio threshold, it is determined that the echo signal does not exist in the signal to be detected.

[0293] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0294] Determining, according to different candidate Doppler frequency shift values, a plurality of estimated signals corresponding to each candidate Doppler frequency shift value;

[0295] Obtaining a signal difference between the signal to be detected and each of the estimated signals;

[0296] The candidate Doppler frequency shift value corresponding to the estimated signal corresponding to the minimum signal difference is used as the first Doppler frequency shift value.

[0297] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0298] When the Doppler shift type is that the frequency shifts of the signal components are inconsistent, determining at least one valid path from the signal transmission paths according to the signal components;

[0299] Echo detection is performed on the signal to be detected according to the multiple valid signals corresponding to each of the valid paths.

[0300] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0301] Acquire, according to each of the valid signals, a second Doppler frequency shift value corresponding to each of the valid signals, wherein the second Doppler frequency shift value corresponding to each of the valid signals is different;

[0302] Determining distance data corresponding to each of the valid signals according to each of the valid signals and each of the second Doppler frequency shift values, wherein the distance data includes a first amplitude value, and the first amplitude value is used to represent the maximum radiation intensity of the valid signal;

[0303] Perform echo detection on the signal to be detected according to each of the distance data.

[0304] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0305] Adding the first amplitude values corresponding to the valid signals to obtain an amplitude sum value;

[0306] If the amplitude value and value are greater than or equal to a preset sum value threshold, it is determined that an echo signal exists in the signal to be detected;

[0307] If the amplitude value and value are smaller than the preset value threshold, it is determined that there is no echo signal in the signal to be detected.

[0308] In one embodiment, the distance data further includes amplitude delay, and when the computer program is executed by the processor, the following steps are further implemented:

[0309] Determine, according to the amplitude value, the amplitude delay, and the second Doppler frequency shift value corresponding to each of the valid signals, a first energy value corresponding to each of the valid signals, and obtain an energy value and value of each of the first energy values;

[0310] determining, according to the signal to be detected, a second energy value corresponding to the signal to be detected;

[0311] If the energy ratio of the energy value sum to the second energy value is greater than or equal to a second ratio threshold, determining that an echo signal exists in the signal to be detected;

[0312] If the energy ratio of the energy value sum to the second energy value is less than a second ratio threshold, it is determined that no echo signal exists in the signal to be detected.

[0313] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0314] Determining, according to each of the signal components, a second amplitude value corresponding to each of the signal components;

[0315] The signal transmission path corresponding to the signal whose second amplitude value is greater than a preset amplitude value threshold is used as the valid path.

[0316] In one embodiment, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the following steps:

[0317] Acquire a signal to be detected in a preset time window, wherein the signal to be detected includes multiple signals corresponding to multiple signal transmission paths;

[0318] determining, according to the signal to be detected, a Doppler shift type of the signal to be detected, the Doppler shift type including: a consistent frequency shift of each signal component or a inconsistent frequency shift of each signal component;

[0319] According to the Doppler frequency shift type, echo detection is performed on the signal to be detected to determine whether the signal to be detected includes an echo signal.

[0320] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0321] In a case where the Doppler shift type is that the frequency shifts of the signal components are consistent, determining a first Doppler shift value corresponding to each of the signal components according to the signal to be detected, the first Doppler shift value corresponding to each of the signal components being the same;

[0322] Echo detection is performed on the signal to be detected according to the signal to be detected and the first Doppler frequency shift values corresponding to the signal components.

[0323] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0324] Determining, based on the signal to be detected and each of the first Doppler frequency shift values, a first probability density and a second probability density corresponding to the signal to be detected, wherein the first probability density is used to characterize the probability distribution of the presence of the echo signal in the signal to be detected, and the second probability density is used to characterize the probability distribution of the absence of the echo signal in the signal to be detected;

[0325] Echo detection is performed on the signal to be detected according to a probability density ratio of the first probability density to the second probability density.

[0326] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0327] When the probability density ratio is greater than or equal to a first ratio threshold, determining that the echo signal exists in the signal to be detected;

[0328] When the probability density ratio is less than the first ratio threshold, it is determined that the echo signal does not exist in the signal to be detected.

[0329] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0330] Determining, according to different candidate Doppler frequency shift values, a plurality of estimated signals corresponding to each candidate Doppler frequency shift value;

[0331] Obtaining a signal difference between the signal to be detected and each of the estimated signals;

[0332] The candidate Doppler frequency shift value corresponding to the estimated signal corresponding to the minimum signal difference is used as the first Doppler frequency shift value.

[0333] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0334] When the Doppler shift type is that the frequency shifts of the signal components are inconsistent, determining at least one valid path from the signal transmission paths according to the signal components;

[0335] Echo detection is performed on the signal to be detected according to the multiple valid signals corresponding to each of the valid paths.

[0336] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0337] Acquire, according to each of the valid signals, a second Doppler frequency shift value corresponding to each of the valid signals, wherein the second Doppler frequency shift value corresponding to each of the valid signals is different;

[0338] Determining distance data corresponding to each of the valid signals according to each of the valid signals and each of the second Doppler frequency shift values, wherein the distance data includes a first amplitude value, and the first amplitude value is used to represent the maximum radiation intensity of the valid signal;

[0339] Perform echo detection on the signal to be detected according to each of the distance data.

[0340] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0341] Adding the first amplitude values corresponding to the valid signals to obtain an amplitude sum value;

[0342] If the amplitude value and value are greater than or equal to a preset sum value threshold, it is determined that an echo signal exists in the signal to be detected;

[0343] If the amplitude value and value are smaller than the preset value threshold, it is determined that there is no echo signal in the signal to be detected.

[0344] In one embodiment, the distance data further includes amplitude delay, and when the computer program is executed by the processor, the following steps are further implemented:

[0345] Determine, according to the amplitude value, the amplitude delay, and the second Doppler frequency shift value corresponding to each of the valid signals, a first energy value corresponding to each of the valid signals, and obtain an energy value and value of each of the first energy values;

[0346] determining, according to the signal to be detected, a second energy value corresponding to the signal to be detected;

[0347] If the energy ratio of the energy value sum to the second energy value is greater than or equal to a second ratio threshold, determining that an echo signal exists in the signal to be detected;

[0348] If the energy ratio of the energy value sum to the second energy value is less than a second ratio threshold, it is determined that no echo signal exists in the signal to be detected.

[0349] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0350] Determining, according to each of the signal components, a second amplitude value corresponding to each of the signal components;

[0351] The signal transmission path corresponding to the signal whose second amplitude value is greater than a preset amplitude value threshold is used as the valid path.

[0352] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0353] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, database or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processor involved in the various embodiments provided herein may be, but are not limited to, a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, and the like.

[0354] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0355] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A target echo detection method for a multi-carrier underwater acoustic communication and perception integrated system, characterized in that: The method comprises: Acquire a signal to be detected in a preset time window, wherein the signal to be detected includes multiple signals corresponding to multiple signal transmission paths; determining, according to the signal to be detected, a Doppler shift type of the signal to be detected, the Doppler shift type including: a consistent frequency shift of each signal component or a inconsistent frequency shift of each signal component; According to the Doppler frequency shift type, echo detection is performed on the signal to be detected to determine whether the signal to be detected includes an echo signal.

2. The method according to claim 1, characterized in that The performing echo detection on the signal to be detected according to the Doppler frequency shift type includes: In a case where the Doppler shift type is that the frequency shifts of the signal components are consistent, determining a first Doppler shift value corresponding to each of the signal components according to the signal to be detected, the first Doppler shift value corresponding to each of the signal components being the same; Echo detection is performed on the signal to be detected according to the signal to be detected and the first Doppler frequency shift values corresponding to the signal components.

3. The method according to claim 2, characterized in that The performing echo detection on the signal to be detected according to the signal to be detected and the first Doppler frequency shift value corresponding to each of the signal components includes: Determining, according to the signal to be detected and each of the first Doppler shift values, a first probability density and a second probability density corresponding to the signal to be detected, wherein the first probability density is used to characterize the probability distribution of the presence of the echo signal in the signal to be detected, and the second probability density is used to characterize the probability distribution of the absence of the echo signal in the signal to be detected; Echo detection is performed on the signal to be detected according to a probability density ratio of the first probability density to the second probability density.

4. The method according to claim 3, characterized in that The performing echo detection on the signal to be detected according to the probability density ratio of the first probability density and the second probability density includes: When the probability density ratio is greater than or equal to a first ratio threshold, determining that the echo signal exists in the signal to be detected; When the probability density ratio is less than the first ratio threshold, it is determined that the echo signal does not exist in the signal to be detected.

5. The method according to any one of claims 2 to 4, characterized in that: The determining, according to the signal to be detected, a first Doppler frequency shift value corresponding to each of the signal components includes: Determining, according to different candidate Doppler frequency shift values, a plurality of estimated signals corresponding to each candidate Doppler frequency shift value; Obtaining a signal difference between the signal to be detected and each of the estimated signals; The candidate Doppler frequency shift value corresponding to the estimated signal corresponding to the minimum signal difference is used as the first Doppler frequency shift value.

6. The method according to claim 1, characterized in that The performing echo detection on the signal to be detected according to the Doppler frequency shift type includes: When the Doppler shift type is that the frequency shifts of the signal components are inconsistent, determining at least one valid path from the signal transmission paths according to the signal components; Echo detection is performed on the signal to be detected according to the multiple valid signals corresponding to each of the valid paths.

7. The method according to claim 6, characterized in that The performing echo detection on the signal to be detected according to the multiple valid signals corresponding to each valid path includes: Acquire, according to each of the valid signals, a second Doppler frequency shift value corresponding to each of the valid signals, wherein the second Doppler frequency shift value corresponding to each of the valid signals is different; Determining distance data corresponding to each of the valid signals according to each of the valid signals and each of the second Doppler frequency shift values, wherein the distance data includes a first amplitude value, and the first amplitude value is used to represent the maximum radiation intensity of the valid signal; Perform echo detection on the signal to be detected according to each of the distance data.

8. The method according to claim 7, characterized in that The performing echo detection on the signal to be detected according to each of the distance data includes: Adding the first amplitude values corresponding to the valid signals to obtain an amplitude sum value; If the amplitude value and value are greater than or equal to a preset sum value threshold, it is determined that an echo signal exists in the signal to be detected; If the amplitude value and value are smaller than the preset value threshold, it is determined that there is no echo signal in the signal to be detected.

9. The method according to claim 7, characterized in that The distance data also includes amplitude delay, and performing echo detection on the signal to be detected based on each of the distance data includes: Determining a likelihood ratio test statistic corresponding to each valid signal according to the amplitude value, the amplitude delay, and the second Doppler frequency shift value corresponding to each valid signal; If the likelihood ratio test statistic is greater than or equal to a second ratio threshold, determining that an echo signal exists in the signal to be detected; If the likelihood ratio test statistic is less than a second ratio threshold, it is determined that no echo signal exists in the signal to be detected.

10. The method according to any one of claims 6 to 9, wherein: The determining at least one valid path from each of the signal transmission paths according to each of the signal components includes: Determining, according to each of the signal components, a second amplitude value corresponding to each of the signal components; The signal transmission path corresponding to the signal whose second amplitude value is greater than a preset amplitude value threshold is used as the valid path.

11. A target echo detection method and device for a multi-carrier underwater acoustic communication and perception integrated system, characterized in that: The device comprises: An acquisition module, configured to acquire a signal to be detected in a preset time window, wherein the signal to be detected includes a plurality of signals corresponding to a plurality of signal transmission paths; a determination module, configured to determine a Doppler shift type of the signal to be detected based on the signal to be detected, wherein the Doppler shift type includes that the frequency shifts of the signal components are consistent or that the frequency shifts of the signal components are inconsistent; The echo detection module is configured to perform echo detection on the signal to be detected according to the Doppler frequency shift type to determine whether the signal to be detected includes an echo signal.

12. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 10 are implemented.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 10 are implemented.

14. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 10 are implemented.

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