Dual-channel positive and negative frequency modulation signal processing method, device, equipment, medium and product

Abstract

The invention discloses a dual-channel positive and negative frequency modulation signal processing method and device, equipment, a medium and a product, and relates to the field of underwater detection, and the method comprises the steps: a first channel and a second channel in a dual-channel transducer respectively transmit a positive frequency modulation signal s1 and a negative frequency modulation signal s2 to a target; after target reflection, the signal received by the first channel is y1, and the signal received by the second channel is y2; performing down-mixing processing on the received signals y1 and y2; carrying out low-pass filtering on the signal subjected to the down-mixing processing; carrying out downsampling on the signal after low-pass filtering; performing pulse compression on the downsampled signal; and performing envelope calculation on the signal after pulse compression. According to the invention, the signal-to-noise ratio of the signal is improved, and the target identification precision is improved.

Description

Technical Field

[0001] The present application relates to the field of underwater detection, and in particular to a dual-channel positive and negative frequency modulation signal processing method, device, equipment, medium and product. Background Art

[0002] In the field of underwater detection technology, with the growing demand for underwater biological and resource assessment, the application of fishing sonar has also increased. Sonar technology is mainly divided into single beam, split beam and multi-beam types according to the emission method of the sound wave beam. Single beam sonar, as a widely used underwater detection equipment, includes single beam depth sounding sonar and mechanical rotary sonar. Due to its simple structure, it is widely used in underwater robot systems such as underwater sediment measurement and seabed obstacle avoidance. However, single beam sonar has some limitations in practical applications, such as high side lobes and wide main lobes resulting in limited resolution, inability to automatically detect and identify small targets, and slow scanning speed, which affects the real-time detection.

[0003] On the other hand, although multi-channel sonar can provide more comprehensive, detailed and higher-resolution detection data, its design and manufacturing process is relatively complex, requiring high-end instrument manufacturing technology and precision sonar sensors, so the cost is relatively high. In addition, multi-beam systems have higher requirements for computing and storage devices when processing large amounts of data, which also limits their widespread use in certain application scenarios.

[0004] In view of the above background, the present invention aims to solve the deficiencies of existing single-beam sonar in terms of resolution, target recognition and real-time performance, while reducing the cost and data processing requirements of multi-channel sonar systems to meet the needs of underwater detection technology development and promote the efficiency and accuracy of underwater resource assessment and biological detection. Through innovative technical solutions, the present invention aims to provide a signal processing method for dual-channel positive and negative frequency modulation that is both economical and efficient to meet the growing market demand for underwater detection. Summary of the invention

[0005] The purpose of this application is to provide a dual-channel positive and negative frequency modulation signal processing method, device, equipment, medium and product, which can improve the signal-to-noise ratio of the signal and thus improve the recognition accuracy of the target.

[0006] To achieve the above objectives, this application provides the following solutions:

[0007] In a first aspect, the present application provides a dual-channel positive and negative frequency modulation signal processing method, comprising:

[0008] The first channel and the second channel of the dual-channel transducer transmit a positive frequency modulation signal s1 and a negative frequency modulation signal s2 to the target respectively;

[0009] After being reflected by the target, the signal received by the first channel is y1, and the signal received by the second channel is y2;

[0010] Perform down-conversion processing on the received signals y1 and y2;

[0011] Perform low-pass filtering on the signal after down-conversion processing;

[0012] Perform down-sampling on the signal after low-pass filtering;

[0013] Perform pulse compression on the signal after down-sampling;

[0014] Obtain the envelope of the signal after pulse compression.

[0015] Optionally, the expression of the positive frequency modulation signal s1 is: s1 = cos(2πf1t + πkt 2 )

[0016] The expression of the negative frequency modulation signal s2 is: s2 = cos(2πf2t - πkt 2 )

[0017] Wherein, f1 and f2 are carrier frequencies, the frequency modulation signal bandwidth is f1~f2, and f1 < f2, k = bw / T, bw is the signal bandwidth, T is the signal pulse width, and t represents the sampling time;

[0018] The specific formula for performing down-conversion processing on the received signals y1 and y2 is as follows:

[0019] y DDC1 = y1·cos(2f1t) - 1j·y1·sin(2f1t)

[0020] y DDC2 = y2·cos(2f1t) - 1j·y2·sin(2f1t)

[0021] Wherein, y DDC1 represents the complex signal generated by the first channel after down-conversion, y DDC2 represents the complex signal generated by the second channel after down-conversion, f1 and f2 are carrier frequencies, and j represents the imaginary unit.

[0022] Optionally, the specific formula for performing low-pass filtering on the signal after down-conversion processing is as follows:

[0023]

[0024]

[0025] Wherein, y LP1 represents the complex signal output by the first channel after passing through the low-pass filter, yLP2 represents the complex signal output by the second channel after passing through the low-pass filter, y DDC1 Represents the complex signal output by the first channel after the down-mixing module, y DDC2 represents the complex signal output by the second channel after the down-mixing module, f c represents the cutoff frequency of the filter, t represents the sampling time, and * represents the convolution operation.

[0026] Optionally, downsampling the signal after low-pass filtering is performed using the following formula:

[0027]

[0028] Among them, y DSR1 (t) represents the complex signal output by the first channel after downsampling, y DSR2 (t) represents the complex signal output by the second channel after downsampling, y LP1 represents the complex signal output by the first channel after passing through the low-pass filter, y LP2 represents the complex signal output by the second channel after passing through the low-pass filter, DSR represents the downsampling rate, and t represents the sampling time.

[0029] Optionally, the pulse compression of the downsampled signal specifically adopts the following formula:

[0030] y mf1_re =y DSR1_re *F 1_re -y DSR1_im *F 1_im

[0031] y mf1_im =y DSR1_re *F 1_im +y DSR1_im *F 1_re

[0032] y mf2_re =y DSR2_re *F 2_re -y DSR2_im *F 2_im

[0033] y mf2_im =y DSR2_re *F 2_im +y DSR2_im *F 2_re

[0034] Among them, y mf1 represents the complex signal output by the first channel after pulse compression, y mf2 represents the complex signal output by the second channel after pulse compression; y DSR1_reRepresents the real part of the complex signal output by the first channel after downsampling, y DSR2_re Represents the real part of the complex signal output by the second channel after downsampling; y DSR1_im Represents the imaginary part of the complex signal output by the first channel after downsampling, y DSR2_im Represents the imaginary part of the complex signal output by the second channel after downsampling;

[0035] y DSR1_im Represents the imaginary part of the complex signal output by the first channel after downsampling, y DSR2_im Represents the imaginary part of the complex signal output by the second channel after downsampling;

[0036] y mf1 =y mf1_re +1j·y mf1_im

[0037] y mf2 =y mf2_re +1j·y mf2_im

[0038] y mf1_re represents the real part of the complex signal output by the first channel after pulse compression, y mf2_re Represents the real part of the complex signal output by the second channel after pulse compression;

[0039] y mf1_im represents the imaginary part of the complex signal output by the first channel after pulse compression, y mf2_im Represents the imaginary part of the complex signal output by the second channel after pulse compression.

[0040] F1 is a local complex signal pre-stored in the receiving link of the first channel, and F2 is a local signal pre-stored in the receiving link of the second channel:

[0041] F1=F 1_re +1j·F 1_im

[0042] F2=F 2_re +1j·F 2_im

[0043] F 1_re is the real part of the local complex signal pre-stored in the receiving link of the first channel, F 2_re is the real part of the local complex signal pre-stored in the receiving link of the second channel, F 1_im is the imaginary part of the local complex signal pre-stored in the receiving link of the first channel, F 2_im is the imaginary part of the local complex signal pre-stored in the receiving link of the second channel.

[0044] Optionally, the envelope of the pulse compressed signal is obtained by using the following formula:

[0045]

[0046] Among them, z1 represents the output signal of the first channel after envelope calculation, z2 represents the output signal of the second channel after envelope calculation, and y mf1_re represents the real part of the complex signal output by the first channel after pulse compression, y mf1_im represents the imaginary part of the complex signal output by the first channel after pulse compression, y mf2_re represents the real part of the complex signal output by the second channel after pulse compression, y mf2_im Represents the imaginary part of the complex signal output by the second channel after pulse compression.

[0047] In a second aspect, the present application provides a dual-channel positive and negative frequency modulation signal processing device, comprising:

[0048] A transmission signal acquisition module, used to use the first channel and the second channel of the dual-channel transducer to transmit a positive frequency modulation signal s1 and a negative frequency modulation signal s2 to the target respectively;

[0049] The receiving signal acquisition module, after being reflected by the target, the signal received by the first channel is y1, and the signal received by the second channel is y2;

[0050] A down-mixing processing module, used for performing down-mixing processing on the received signals y1 and y2;

[0051] A low-pass filtering module, used for performing low-pass filtering on the signal after the down-mixing processing;

[0052] A downsampling module, used for downsampling the signal after low-pass filtering;

[0053] A pulse compression module, used for performing pulse compression on the downsampled signal;

[0054] The envelope obtaining module is used to obtain the envelope of the pulse compressed signal.

[0055] In a third aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the dual-channel positive and negative frequency modulation signal processing method described in any one of the above.

[0056] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the above-described dual-channel positive and negative frequency modulation signal processing methods.

[0057] In a fifth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the steps of any of the above-mentioned dual-channel positive and negative frequency modulation signal processing methods.

[0058] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0059] The present application provides a dual-channel positive and negative frequency modulation signal processing method, device, equipment, medium and product. The first channel in the dual-channel transducer transmits positive frequency modulation, and the receiving link of the first channel also stores positive frequency modulation signals, while the second channel transmits negative frequency modulation, and the receiving link of the second channel also stores negative frequency modulation. When the target is located near the sound line of the first channel, the signal emitted by the first channel can only be effectively pulse compressed with the local signal of the first channel after reflection and generate one peak value, but cannot generate a peak value with the local signal in the second channel. Therefore, only one bright spot will appear on the user interface of the host computer, and because of the pulse compression, the signal-to-noise ratio is higher, purer and more reliable. Therefore, when it is transmitted to the host computer for interface display, it is less affected by non-target objects such as noise, and the user interface is clearer during use, thereby improving the efficiency and accuracy of biological detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. 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 creative work.

[0061] Figure 1 This is a schematic diagram of the arrangement of dual-channel transducers in one embodiment of the present application;

[0062] Figure 2 This is a flow chart of a signal processing method for dual-channel positive and negative frequency modulation in one embodiment of the present application;

[0063] Figure 3 A schematic diagram of a dual-channel positive and negative frequency modulation signal processing method provided in one embodiment of the present application;

[0064] Figure 4 The change of amplitude with frequency in the 22.5° direction provided in an embodiment of the present application;

[0065] Figure 5 A schematic diagram of the result after obtaining the envelope provided in an embodiment of the present application;

[0066] Figure 6A schematic diagram of test results of a test on an anechoic pool provided in an embodiment of the present application;

[0067] Figure 7 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0068] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0069] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0070] Figure 1 This is a schematic diagram of the arrangement of dual-channel transducers in one embodiment of the present application, see Figure 1 , label 1 is a dual-channel transducer, 2 is the sound line, that is, the propagation path of the transmitted waveform, representing the propagation direction of the wave; 3 is the main lobe of the beam, which is usually aligned with the center of the sensor array, reflecting the main observation or transmission direction of the system. The main lobe interval of the two channels is 22.5°.

[0071] Figure 2 1 is a flow chart of a signal processing method for dual-channel positive and negative frequency modulation in one embodiment of the present application. Figure 3 A schematic diagram of a dual-channel positive and negative frequency modulation signal processing method provided in an embodiment of the present application, combined with Figure 2 and Figure 3 The signal processing method of dual-channel positive and negative frequency modulation in this application specifically includes the following steps:

[0072] Step 101: The first channel and the second channel of the dual-channel transducer transmit a positive frequency modulation signal s1 and a negative frequency modulation signal s2 to a target respectively.

[0073] The dual-channel transducer transmitter part includes two channels, the first channel and the second channel. The two channels transmit different FM signals respectively. The first channel transmits the positive FM signal s1:

[0074] s1=cos(2πf1t+πkt 2 )

[0075] The second channel transmits a negative frequency modulated signal s2:

[0076] s2=cos(2πf2t-πkt 2 )

[0077] The bandwidth of the frequency-modulated signal is f1 to f2, and f1 < f2. k = bw / T, where bw is the signal bandwidth, T is the signal pulse width, and f1 and f2 are the carrier frequencies.

[0078] Step 102: After being reflected by the target, the signal received by the first channel is y1, and the signal received by the second channel is y2.

[0079] When starting to receive, the acoustic wave signal received by the first channel after being reflected by the target is y1, and the acoustic wave signal received by the second channel after being reflected by the target is y2. Both acoustic wave signals usually contain noise.

[0080] Step 103: Perform down-conversion processing on the received signals y1 and y2.

[0081] Perform down-conversion on the received signal. The purpose of down-conversion is to shift the high-frequency signal to the low-frequency. The mixing formula is as follows:

[0082] y DDC1 = y1·cos(2f1t) - 1j·y1·sin(2f1t)

[0083] y DDC2 = y2·cos(2f1t) - 1j·y2·sin(2f1t)

[0084] Mixing will result in a real part and an imaginary part. Therefore, subsequent signals are all complex signals.

[0085] Step 104: Perform low-pass filtering on the signal after down-conversion processing.

[0086] According to the sampling theorem, mixing will bring about the problem of image frequency. Therefore, perform low-pass filtering on the signal after down-conversion. The filtered signals are y LP1 and y LP2 .

[0087]

[0088] where * is the convolution operation, and f c is the cut-off frequency of the filter.

[0089] Step 105: Perform downsampling on the signal after low-pass filtering.

[0090] Perform downsampling on the signal after low-pass filtering. While maintaining the important features of the signal unchanged, reduce the computational complexity and lower the data rate. The output signals are y DSR1 and y DSR2 , and the downsampling rate can be adjusted according to the hardware requirements. The formula is as follows:

[0091]

[0092] Wherein, DSR is the sampling rate, which is an integer, indicating that one data is taken every DSR sampling points.

[0093] Step 106: Perform pulse compression on the downsampled signal.

[0094] In order to improve the distance resolution and increase the signal-to-noise ratio, pulse compression is used to match the two models with the local signal respectively. The complex convolution formula is as follows:

[0095] y mf1_re =y DSR1_re *F 1_re -y DSR1_im *F 1_im

[0096] y mf1_im =y DSR1_re *F 1_im +y DSR1_im *F 1_re

[0097] y mf2_re =y DSR2_re *F 2_re -y DSR2_im *F 2_im

[0098] y mf2_im =y DSR2_re *F 2_im +y DSR2_im *F 2_re

[0099] Among them, y mf1 With y mf2 is the signal output after matched filtering, which is a complex signal:

[0100] y mf1 =y mf1_re +1j·y mf1_im

[0101] y mf2 =y mf2_re +1j·y mf2_im

[0102] y mf1_re and mf2_re is the real part of the signal, y mf1_im With y mf2_im is the imaginary part of the signal.

[0103] F1 and F2 are local signals, that is, the ideal transmitted signals s1 and s2 are processed in the same way as the received signals, and are also complex signals:

[0104] F1=F 1_re +1j·F 1_im

[0105] F2=F 2_re +1j·F 2_im

[0106] F 1_re and F 2_re is the real part of the signal, F 1_im With F 2_im is the imaginary part of the signal

[0107] Step 107: Obtain the envelope of the pulse compressed signal.

[0108] The signal after pulse compression is subjected to complex modulus calculation, that is, the envelope is obtained. The formula is as follows:

[0109]

[0110] Among them, z1 and z2 are the data obtained after envelope calculation. Since the data has been pulse compressed, the signal-to-noise ratio is higher, and it is purer and more reliable. Therefore, when it is transmitted to the host computer for interface display, it is less affected by non-target objects such as noise, and the user interface is clearer during use.

[0111] Simulation and experimental testing

[0112] The length of a single transducer used in the simulation is 14 cm. The directivity of the transducer is simulated according to the linear array beamforming. The array spacing is about λ / 2, where λ is the wavelength. The directivity amplitude in the 22.5° direction is related to the frequency change of the FM signal and the amplitude decreases by about -35 dB relative to the main lobe. The amplitude changes with frequency as shown in Figure 4 shown.

[0113] During the simulation, the pulse width of the transmitted signal is 0.1ms, and the signals of the first channel (the channel transmitting the positive frequency modulation signal) received by the simulated receiver at the 0° and 22.5° directions are s1 and s2, respectively. 1_225 (Ideally, no noise or channel loss is added.) 1_225 Matched filtering is performed with F1 and F2 respectively, and the results after obtaining the envelope are as follows Figure 5 shown.

[0114] Depend on Figure 5 It can be seen that the main lobe amplitude after s1 and F1 match is the same as s 1_225 The main lobe amplitude after matching with F1 is about 40dB different, s 1_225 The maximum amplitude after matching with F1 and s 1_225The main lobe amplitude after matching with F1 differs by about 10dB, and the maximum amplitude after matching s1 and F2 (purple line) differs by about 10dB from the main lobe amplitude after matching s1 and F1 (blue line).

[0115] That is, compared with a single channel, in a dual-channel transducer using positive and negative frequency modulation signals, the second transducer has less influence on the first transducer during the received signal processing.

[0116] The relevant tests were carried out in the anechoic pool, and the transducer was self-transmitted and self-received. The test results are as follows Figure 6 As shown in the results, the directivity amplitude of the first channel at 22.5° is reduced by about -24dB compared to that at 0°, and the main lobe amplitude after s1 and F1 are matched is similar to s 1_22 The main lobe amplitudes of F5 and F1 after matching differ by about 25dB. 1_225 There is no obvious amplitude after matching with F2, but the maximum amplitude is similar to s 1_225 The main lobe amplitude after matching with F1 is about 10dB different. Since the transducer will introduce errors in the manufacturing process, the amplitude of the transducer directivity in the 22.5° direction is -24dB, which is about 10dB higher than the simulation, so it will have a certain impact on the measured matching results.

[0117] Based on the same inventive concept, the embodiment of the present application also provides a dual-channel positive and negative frequency modulation signal processing device for implementing the dual-channel positive and negative frequency modulation signal processing method involved above. The implementation solution provided by the device to solve the problem is similar to the implementation solution recorded in the above method, so the specific limitations in the one or more dual-channel positive and negative frequency modulation signal processing device embodiments provided below can refer to the limitations of the dual-channel positive and negative frequency modulation signal processing method above, and will not be repeated here.

[0118] In an exemplary embodiment, a dual-channel positive and negative frequency modulation signal processing device is provided, comprising:

[0119] A transmission signal acquisition module, used to use the first channel and the second channel of the dual-channel transducer to transmit a positive frequency modulation signal s1 and a negative frequency modulation signal s2 to the target respectively;

[0120] The receiving signal acquisition module, after being reflected by the target, the signal received by the first channel is y1, and the signal received by the second channel is y2;

[0121] A down-mixing processing module, used for performing down-mixing processing on the received signals y1 and y2;

[0122] A low-pass filtering module, used for performing low-pass filtering on the signal after the down-mixing processing;

[0123] A downsampling module, used for downsampling the signal after low-pass filtering;

[0124] A pulse compression module, used for performing pulse compression on the downsampled signal;

[0125] The envelope obtaining module is used to obtain the envelope of the pulse compressed signal.

[0126] In summary, the above scheme in this application has the following beneficial effects:

[0127] The traditional transmission method is to transmit the same signal to each channel, such as the first channel and the second channel transmitting signals at the same time. When the signal reaches the target, it is reflected to the first channel and the second channel. At this time, the receivers of the first channel and the second channel start working. The signal of the first channel will partially enter the second channel. If pulse compression is performed, a peak will be generated. This result will affect the judgment of the target direction, number, etc. For example, an object is close to the sound line emitted by the first channel, but because the transmission of the first channel and the second channel is consistent with the locally pre-stored signal, when the sound wave reaches the target, its echo will not only produce a peak after pulse compression with the first channel, but also produce a peak after pulse compression with the second channel. In the display of the upper computer interface, there was originally only one bright spot, but due to the interference of the second channel, two bright spots will appear.

[0128] The present application effectively avoids this problem. For example, the first channel transmits positive FM, and the receiving link of the first channel also stores positive FM signals, while the second channel transmits negative FM, and the receiving link of the second channel also stores negative FM. When the target is near the sound line of the first channel, the signal transmitted by the first channel can only be effectively pulse compressed with the local signal of the first channel after reflection and produce one peak value, but cannot produce a peak value with the local signal in the second channel. Therefore, only one bright spot will appear in the upper computer user interface.

[0129] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Figure 7As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through 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 signal processing data of dual-channel positive and negative frequency modulation. 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 through a network connection. When the computer program is executed by the processor, a signal processing method of dual-channel positive and negative frequency modulation is implemented.

[0130] Those skilled in the art will understand that Figure 7 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 those shown in the figure, or combine certain components, or have a different arrangement of components.

[0131] In an exemplary embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0132] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0133] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0134] 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.

[0135] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed 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 the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0136] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0137] The technical features of the above embodiments may 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.

[0138] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A dual-channel positive and negative frequency modulation signal processing method, characterized in that: The signal processing method for dual-channel positive and negative frequency modulation includes: The first channel and the second channel in the dual-channel transducer respectively transmit a positive frequency modulation signal s1 and a negative frequency modulation signal s2 to the target; After being reflected by the target, the signal received by the first channel is y1, and the signal received by the second channel is y2; Perform down-conversion processing on the received signals y1 and y2; Perform low-pass filtering on the signals after down-conversion processing; Perform down-sampling on the signals after low-pass filtering; Perform pulse compression on the signals after down-sampling; Obtain the envelope of the signals after pulse compression.

2. The signal processing method of dual-channel positive and negative frequency modulation according to claim 1, characterized in that: The expression of the positive frequency modulation signal s1 is: s1 = cos(2πf1t+πkt 2 ) The expression of negative frequency modulation signal s2 is: s2 = cos(2πf2t-πkt 2 ) Wherein, f1 and f2 are carrier frequencies, the frequency modulation signal bandwidth is f1~f2, and f1 < f2, k = bw / T, bw is the signal bandwidth, T is the signal pulse width, and t is the sampling time; The specific formula for performing down-conversion processing on the received signals y1 and y2 is as follows: y DDC1 =y1·cos(2f1t)-1j·y1·sin(2f1t) <h2 style=";text-align:left;direction:ltr">y<h2 style=";text-align:left;direction:ltr"> DDC2 <h2 style=";text-align:left;direction:ltr"> =y2 cos(2f1t)-1j y2 sin(2f1t) Among them, y DDC1 represents the complex signal generated by the first channel after down-mixing, y DDC2 It represents the complex signal generated by the second channel after down-mixing, f1 and f2 are the carrier frequencies, and j represents the imaginary unit.

3. The signal processing method of dual-channel positive and negative frequency modulation according to claim 1, characterized in that: The specific formula for performing low-pass filtering on the signals after down-conversion processing is as follows: Among them, y LP1 represents the complex signal output by the first channel after passing through the low-pass filter, y LP2 represents the complex signal output by the second channel after passing through the low-pass filter, y DDC1 represents the complex signal output by the first channel after down-mixing, y DDC2 represents the complex signal output by the second channel after down-mixing, f c represents the cutoff frequency of the filter, t represents the sampling time, and * represents the convolution operation.

4. The signal processing method of dual-channel positive and negative frequency modulation according to claim 1, characterized in that: The specific formula for performing down-sampling on the signals after low-pass filtering is as follows: Among them, y DSR1 (t) represents the complex signal output by the first channel after downsampling, y DSR2 (t) represents the complex signal output by the second channel after downsampling, y LP1 represents the complex signal output by the first channel after being processed by the low-pass filter, y LP2 represents the complex signal output by the second channel after being processed by the low-pass filter, DSR represents the downsampling rate, and t represents the sampling time.

5. The signal processing method of dual-channel positive and negative frequency modulation according to claim 1, characterized in that: The specific formula for performing pulse compression on the signals after down-sampling is as follows: y mf1_re =y DSR1_re *F 1_re -y DSR1_in *F 1_im y mf1_im =y DSR1_re *F 1_im +y DSR1_im *F 1_re y mf2_re =y DSR2_ re*F 2_re -y DSR2_im *F 2_im y mf2_im =y DSR2_re *F 2_im +y DSR2_im *F 2_re Among them, y mf1 represents the complex signal output by the first channel after pulse compression, y mf2 represents the complex signal output by the second channel after pulse compression; y DSR1_re Represents the real part of the complex signal output by the first channel after downsampling, y DSR2_re Represents the real part of the complex signal output by the second channel after downsampling; y DSR1_im Represents the imaginary part of the complex signal output by the first channel after downsampling, y DSR2_im Represents the imaginary part of the complex signal output by the second channel after downsampling; y mf1 =y mf1_re +1j·y mf1_im y mf2 =y mf2_re +1j·y mf2_im y mf1_re represents the real part of the complex signal output by the first channel after pulse compression, y mf2_re Represents the real part of the complex signal output by the second channel after pulse compression; y mf1_im represents the imaginary part of the complex signal output by the first channel after pulse compression, y mf2_im represents the imaginary part of the complex signal output by the second channel after pulse compression; F1 is the local complex signal pre-stored in the receiving link of the first channel, and F2 is the local signal pre-stored in the receiving link of the second channel: F1=F 1_re +1j F 1_im F2=F 2_re +1j·F 2_im F 1_re is the real part of the local complex signal pre-stored in the receiving link of the first channel, F 2_re is the real part of the local complex signal pre-stored in the receiving link of the second channel, F 1_im is the imaginary part of the local complex signal pre-stored in the receiving link of the first channel, F 2_im is the imaginary part of the local complex signal pre-stored in the receiving link of the second channel.

6. The signal processing method of dual-channel positive and negative frequency modulation according to claim 1, characterized in that: The specific formula for obtaining the envelope of the signals after pulse compression is as follows: Among them, z1 represents the output signal of the first channel after envelope calculation, z2 represents the output signal of the second channel after envelope calculation, and y mf1_re represents the real part of the complex signal output by the first channel after pulse compression, y mf1_im represents the imaginary part of the complex signal output by the first channel after pulse compression, y mf2_re represents the real part of the complex signal output by the second channel after pulse compression, y mf2_im Represents the imaginary part of the complex signal output by the second channel after pulse compression.

7. A dual-channel positive and negative frequency modulation signal processing device, characterized in that: The signal processing device for dual-channel positive and negative frequency modulation includes: A transmitting signal acquisition module, which is used to use the first channel and the second channel in the dual-channel transducer to respectively transmit a positive frequency modulation signal s1 and a negative frequency modulation signal s2 to the target; A receiving signal acquisition module, after being reflected by the target, the signal received by the first channel is y1, and the signal received by the second channel is y2; A down-conversion processing module, which is used to perform down-conversion processing on the received signals y1 and y2; A low-pass filtering module, which is used to perform low-pass filtering on the signals after down-conversion processing; A down-sampling module, which is used to perform down-sampling on the signals after low-pass filtering; A pulse compression module, which is used to perform pulse compression on the signals after down-sampling; An envelope obtaining module, which is used to obtain the envelope of the signals after pulse compression.

8. A computer device comprising: A memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the signal processing method for dual-channel positive and negative frequency modulation according to any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the steps of the signal processing method for dual-channel positive and negative frequency modulation according to any one of claims 1-6.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by the processor, it implements the steps of the signal processing method for dual-channel positive and negative frequency modulation according to any one of claims 1-6.

Images