A single-vector hydrophone OFDM-chirp integrated waveform modulation and dual-function implementation method, program, device and storage medium

Abstract

The present application belongs to the technical field of underwater acoustic communication and sensing integration, and particularly relates to a single vector hydrophone OFDM-Chirp integrated waveform modulation and dual-function implementation method, program, device and storage medium. The present application is based on a single vector hydrophone and utilizes a conventional OFDM modulation mode. On the premise of not affecting the orthogonality between subcarriers, a Chirp-LFM signal is embedded into an OFDM waveform to generate a uniform comb pilot OFDM-Chirp integrated signal, thereby realizing the communication and sensing dual functions of an underwater small platform. The embedded complex Chirp pilot signal can be used to realize copy correlation processing at the receiving end for synchronization. The generated OFDM-Chirp integrated waveform no longer needs an additional synchronization header, thereby reducing the time-frequency resource overhead of the system and improving the sensing performance.

Description

Technical Field

[0001] This invention belongs to the field of underwater acoustic communication and sensing integration technology, specifically relating to a method, program, device and storage medium for a single-vector hydrophone OFDM-Chirp integrated waveform modulation and dual-function implementation. Background Technology

[0002] Sound waves are the only information carrier capable of reliable long-distance underwater transmission to date. Underwater acoustic communication and positioning technologies play a crucial role in marine development, underwater target communication, positioning, and navigation. Currently deployed underwater acoustic positioning and navigation systems include long baseline systems, short baseline systems, and ultra-short baseline systems. However, for applications involving clusters of small underwater platforms such as divers and UUVs, these systems suffer from excessive size and weight. In contrast, differential pressure vector hydrophones are small and lightweight, and a single hydrophone can perform direction finding functions without being sensitive to platform movement, making them ideal for installation on small underwater platforms.

[0003] Integrated communication and sensing technology is a current research hotspot in next-generation radio communication technology. OFDM waveforms are favored in the communication field due to their high spectral efficiency and communication speed, while LFM waveforms are favored in the radar sensing field due to their good autocorrelation characteristics and high peak-to-average power ratio of autocorrelation waveforms. Patent CN119135500A discloses an OFDM-LFM integrated communication and sensing signal waveform reception method based on fractional Fourier transform, which converts OFDM subcarriers into LFM signals and uses fractional Fourier transform to modulate the OFDM-LFM integrated waveform. However, research on underwater integrated communication and sensing is still in the exploratory stage, and a systematic solution has not yet been formed for the communication and sensing problem of underwater moving targets, especially small targets.

[0004] Currently, the communication and sensing components of most integrated underwater communication and sensing systems are designed independently. For example, additional time-frequency resources are used to generate a synchronization header for the communication signal, which is then used to perform the sensing function. Furthermore, most current OFDM-LFM integrated waveforms are modulated and demodulated based on LFM subcarriers and fractional Fourier transform. Compared to traditional OFDM modulation methods, this OFDM-LFM scheme occupies a larger bandwidth with the same number of carriers, which poses a challenge for the limited bandwidth resources of underwater acoustic channels. Therefore, a new method and technology are needed to embed Chirp-LFM signals into OFDM waveforms using traditional OFDM modulation methods without affecting the orthogonality between subcarriers, generating an OFDM-Chirp integrated signal to achieve both communication and sensing functions. Summary of the Invention

[0005] The purpose of this invention is to provide a method, program, device, and storage medium for integrating OFDM-Chirp waveform modulation and dual-function implementation of a single-vector hydrophone.

[0006] A method for integrating OFDM-Chirp waveform modulation and dual-function implementation of a single-vector hydrophone includes the following steps:

[0007] The transmitter performs OFDM modulation based on the transmission information and the parameters of the transmitted OFDM baseband signal to obtain a data subcarrier information matrix and a data subcarrier information matrix with added empty carriers. Based on the transmitted OFDM baseband signal parameters, it determines a uniform comb pilot index matrix, a data subcarrier index matrix with added empty carriers, and a complex chirp signal pilot information matrix. According to the index positions given by the uniform comb pilot index matrix, the complex chirp signal pilot information matrix is ​​concatenated with the data subcarrier information matrix with added empty carriers to obtain an OFDM-Chirp hybrid waveform baseband signal. OFDM modulation is then performed on the OFDM-Chirp hybrid waveform baseband signal to obtain an OFDM-Chirp hybrid waveform passband signal. This OFDM-Chirp hybrid waveform passband signal is then transmitted via the transmitter. The complex chirp signal pilot information matrix is ​​then modulated a second time to obtain a time-domain copy waveform of the complex chirp pilot signal, which is then loaded onto the receiver.

[0008] The receiver receives signals through a single-vector hydrophone. It synchronizes the received waveform using a time-domain copy of the complex Chirp pilot signal. Upon successful synchronization, a time delay estimate is obtained. Based on this time delay estimate, the target distance estimate is derived. The received waveform is truncated based on the synchronization result and Doppler compensation is performed to obtain the OFDM-Chirp passband received signals for the sound pressure and vibration velocity channels. OFDM demodulation is applied to the OFDM-Chirp passband received signal for the sound pressure channel to obtain a decoded bitstream, enabling communication. OFDM demodulation is also performed on the OFDM-Chirp passband received signals for both the sound pressure and vibration velocity channels to obtain the OFDM-Chirp baseband received signal. A uniform comb-shaped pilot index matrix is ​​used to extract the receiver pilot information from the OFDM-Chirp baseband received signal and performs secondary modulation to obtain the receiver complex Chirp pilot signals for the sound pressure and vibration velocity channels. The acoustic energy flow method is then used to estimate the target azimuth of the single-vector hydrophone. Combined with the target distance estimate, the sensing function is achieved.

[0009] Furthermore, the transmitting end performs OFDM modulation based on the transmission information and the transmitted OFDM baseband signal parameters to obtain a data subcarrier information matrix and a data subcarrier information matrix with added empty carriers, specifically:

[0010] The transmitter generates a transmit bit stream sequence based on the transmit information, and performs channel coding, interleaving, and QPSK mapping on the transmit bit stream sequence in sequence to obtain the data subcarrier information matrix.

[0011] A null carrier is generated based on the transmitted OFDM baseband signal parameters. The first half of the null carrier is integrated into the front of the data subcarrier information matrix, and the second half of the null carrier is integrated into the back of the data subcarrier information matrix, resulting in a data subcarrier information matrix with the null carrier added.

[0012] Furthermore, the determination of the complex chirp signal pilot information matrix based on the transmitted OFDM baseband signal parameters specifically involves:

[0013] The parameters for transmitting OFDM baseband signals include the OFDM baseband signal pilot spacing. OFDM baseband signal pilot number OFDM baseband signal subcarrier spacing OFDM baseband signal oversampling rate ;

[0014] Construct the complex chirp signal spectrum based on the transmitted OFDM baseband signal parameters:

[0015]

[0016] in, For frequency index, ; This represents the initial number of sampling points for the complex Chirp signal. ; For the oversampling rate of the complex Chirp signal, ; The frequency modulation slope of the complex Chirp signal. ; For the bandwidth of the complex Chirp signal, ; The sampling rate of the complex Chirp signal, ; It is the symbol for imaginary numbers;

[0017] The spectrum of the complex Chirp signal is truncated, with the truncated interval being the point corresponding to the start frequency of frequency modulation and the point corresponding to the end frequency of frequency modulation, to obtain the pilot information matrix of the complex Chirp signal.

[0018] Further, the OFDM modulation of the baseband signal of the OFDM-Chirp hybrid waveform to obtain the OFDM-Chirp hybrid waveform passband signal specifically involves:

[0019] The OFDM-Chirp hybrid waveform baseband signal is sequentially upsampled, subjected to inverse fast Fourier transform, upconverted and real part extracted, cyclic prefix CP is added, and peak-to-average ratio suppression is performed to obtain the OFDM-Chirp hybrid waveform passband signal.

[0020] Furthermore, the vibration velocity channel includes vibration velocity... Channel and vibration velocity aisle;

[0021] The receiving end receives signals through a single-vector hydrophone and synchronizes the received waveform using a time-domain copy waveform of the complex Chirp pilot signal, specifically as follows:

[0022] The receiver uses a time-domain copy waveform of the complex Chirp pilot signal to simultaneously measure the sound pressure channel and vibration velocity of the single-vector hydrophone. Channel and vibration velocity The output signal of the channel is copied and correlated in real time to obtain the copy correlation waveform; when a correlation peak that is significantly higher than the background level is found in the output signal of the single-vector hydrophone, the first correlation peak that exceeds the maximum value of the current copy correlation waveform by K times is selected as the synchronization head position; the value of K is between 0.707 and 0.9.

[0023] Furthermore, the OFDM demodulation of the OFDM-Chirp passband received signals from the sound pressure channel and vibration velocity channel to obtain the OFDM-Chirp baseband received signal is specifically as follows:

[0024] For sound pressure channels and vibration velocity Channel and vibration velocity The OFDM-Chirp passband received signal of the channel is sequentially down-converted, cyclic prefix (CP) removed, fast Fourier transformed, and downsampled to obtain the OFDM-Chirp baseband received signal;

[0025] The process involves extracting receiver pilot information from the OFDM-Chirp baseband received signal using a uniform comb-shaped pilot index matrix and performing secondary modulation to obtain the receiver complex Chirp pilot signals for the sound pressure channel and vibration velocity channel. Specifically:

[0026] The location of the receiver pilot information is determined by the uniform comb pilot index matrix, and then the receiver pilot information is determined by the location of the receiver pilot information and extracted from the OFDM-Chirp baseband received signal.

[0027] The extracted pilot information from the receiving end is arranged in its original order on a one-dimensional empty matrix with a length equal to the number of pilot signals of the OFDM baseband signal, thus obtaining the pilot information matrix from the receiving end.

[0028] The pilot information matrix at the receiving end is modulated twice to obtain the sound pressure channel and vibration velocity. Channel and vibration velocity The receiving end of the channel receives the Chirp pilot signal.

[0029] Furthermore, the secondary modulation includes upsampling, inverse fast Fourier transform, and upconversion;

[0030] The secondary modulation of the complex Chirp signal pilot information matrix is ​​specifically as follows:

[0031] The pilot information matrix of the complex Chirp signal is upsampled to obtain the upsampled pilot frequency domain signal of the complex Chirp signal; the upsampled pilot frequency domain signal of the complex Chirp signal is then subjected to inverse fast Fourier transform and upconversion to obtain the time domain copy waveform of the complex Chirp pilot signal.

[0032] The secondary modulation of the pilot information matrix at the receiving end is specifically as follows:

[0033] The receiver pilot information matrix is ​​upsampled to obtain the upsampled receiver pilot frequency domain signal; the upsampled receiver pilot frequency domain signal is then subjected to inverse fast Fourier transform and upconversion to obtain the sound pressure channel and vibration velocity. Channel and vibration velocity The receiving end of the channel receives the Chirp pilot signal.

[0034] A computer device includes a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the above-described method for integrating single-vector hydrophone OFDM-Chirp waveform modulation and dual-function implementation.

[0035] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method for integrating single-vector hydrophone OFDM-Chirp waveform modulation and dual-function implementation.

[0036] A computer program product includes computer instructions that, when executed by a processor, implement the steps of the above-described method for integrating single-vector hydrophone OFDM-Chirp waveform modulation and dual-function implementation.

[0037] The beneficial effects of this invention are as follows:

[0038] This invention, based on a single-vector hydrophone and utilizing traditional OFDM modulation, embeds a chirp-LFM signal into an OFDM waveform without affecting the orthogonality between subcarriers, generating a uniform comb-shaped pilot OFDM-Chirp integrated signal. This enables dual communication and sensing functions for small underwater platforms. In this invention, the complex chirp pilot signal is completely orthogonal to the other subcarriers, integrating sensing functionality into the existing communication system without affecting the communication performance of the OFDM system.

[0039] This invention utilizes embedded complex chirp pilot signals to achieve synchronization through receiver copy correlation processing. Compared to traditional OFDM signals, the OFDM-Chirp integrated waveform generated by this invention no longer requires an additional synchronization header, reducing system time-frequency resource overhead. The complex chirp pilot signal in this invention exhibits a higher peak-to-average power ratio (PAPR) and a more prominent main peak in its autocorrelation function compared to traditional QPSK pilot signals. Simulation results demonstrate that the OFDM-Chirp integrated waveform has better sensing performance. Each subcarrier of the OFDM-Chirp integrated signal generated by this invention remains a time-domain rectangular CW pulse. Compared to the LFM subcarrier fractional Fourier transform OFDM-LFM modulation method, the OFDM-Chirp integrated waveform generated by this invention has a narrower bandwidth. Attached Figure Description

[0040] Figure 1 The time spectrum diagram of the OFDM-Chirp integrated waveform with uniform comb pilot.

[0041] Figure 2 The bit error rate curve for a uniform comb pilot OFDM-Chirp is shown.

[0042] Figure 3 This is a diagram of the Chirp pilot autocorrelation characteristics.

[0043] Figure 4 This is a diagram showing the autocorrelation characteristics of QPSK pilot signals.

[0044] Figure 5 A comparison diagram of two pilot sensing channel estimation methods when SNR=0dB. Detailed Implementation

[0045] The present invention will now be further described with reference to the accompanying drawings.

[0046] This invention is based on a single-vector hydrophone and utilizes the traditional OFDM modulation method. Without affecting the orthogonality between subcarriers, the Chirp-LFM signal is embedded into the OFDM waveform to generate a uniform comb pilot OFDM-Chirp integrated signal, thereby realizing the dual functions of communication and sensing for small underwater platforms.

[0047] A method for integrating OFDM-Chirp waveform modulation and dual-function implementation of a single-vector hydrophone includes the following steps:

[0048] Step 1: The transmitter generates a transmit bit stream sequence based on the transmit information, and performs channel coding, interleaving, and QPSK mapping on the transmit bit stream sequence in sequence to obtain the data subcarrier information matrix;

[0049] A null carrier is generated based on the transmitted OFDM baseband signal parameters. The first half of the null carrier is integrated into the front of the data subcarrier information matrix, and the second half of the null carrier is integrated into the back of the data subcarrier information matrix to obtain the data subcarrier information matrix with the null carrier added.

[0050] Step 2: Determine the uniform comb pilot index matrix, the data subcarrier index matrix with added empty carriers, and the complex chirp signal pilot information matrix based on the transmitted OFDM baseband signal parameters;

[0051] The determination of the complex chirp signal pilot information matrix based on the transmitted OFDM baseband signal parameters is specifically as follows:

[0052] Step 2.1: The parameters for transmitting the OFDM baseband signal include the OFDM baseband signal pilot spacing. OFDM baseband signal pilot number OFDM baseband signal subcarrier spacing OFDM baseband signal oversampling rate ;

[0053] Based on the transmitted OFDM baseband signal parameters, obtain the first-level parameters of the complex chirp signal, including the complex chirp signal oversampling rate. Chirp signal bandwidth Chirp signal frequency modulation start point Chirp signal frequency modulation endpoint The initial number of sampling points for the complex Chirp signal Chirp signal sampling rate Spectral line spacing of the discrete spectrum of a complex Chirp signal ;

[0054] in, , , , , , ;

[0055] Step 2.2: Based on the first-level parameters of the complex Chirp signal, obtain the second-level parameters of the complex Chirp signal, including the discrete-time axis for the complex Chirp signal. Frequency modulation slope of complex Chirp signal ;

[0056] in, ; ;

[0057] Step 2.3: Based on the second-order parameters of the complex Chirp signal, generate the real part of the complex Chirp signal using the analytical expression of the time-domain waveform of the linear frequency modulated signal, and obtain the analytical form of the complex Chirp signal using the Hilbert transform:

[0058]

[0059] in, ; Indicates a time index;

[0060] Step 2.4: Perform a Discrete Fourier Transform on the analytical form of the complex Chirp signal to obtain the spectrum of the complex Chirp signal:

[0061]

[0062] in, ; Indicates frequency index;

[0063] Step 2.5: Truncate the spectrum of the complex Chirp signal. The truncated interval is from the point corresponding to the start frequency of the frequency modulation to the point corresponding to the end frequency of the frequency modulation, thus obtaining the pilot information matrix of the complex Chirp signal.

[0064] Step 3: Based on the index positions given by the uniform comb pilot index matrix, the complex Chirp signal pilot information matrix is ​​concatenated with the data subcarrier information matrix with added empty carriers to obtain the OFDM-Chirp hybrid waveform baseband signal;

[0065] Step 4: Perform upsampling, inverse fast Fourier transform, upconversion and real part extraction, cyclic prefix (CP) addition, and peak-to-average power ratio (PAPR) suppression sequentially on the OFDM-Chirp hybrid waveform baseband signal to obtain the OFDM-Chirp hybrid waveform passband signal; connect the OFDM-Chirp hybrid waveform passband signal to the transmitter for transmission;

[0066] Step 5: Perform secondary modulation on the complex Chirp signal pilot information matrix to obtain the time-domain copy waveform of the complex Chirp pilot signal, and load the time-domain copy waveform of the complex Chirp pilot signal onto the receiving end;

[0067] The secondary modulation includes upsampling, inverse fast Fourier transform, and upconversion;

[0068] The pilot information matrix of the complex Chirp signal is upsampled to obtain the upsampled pilot frequency domain signal of the complex Chirp signal; the upsampled pilot frequency domain signal of the complex Chirp signal is then subjected to inverse fast Fourier transform and upconversion to obtain the time domain copy waveform of the complex Chirp pilot signal.

[0069] Step 6: The receiver receives the signal through a single-vector hydrophone. It synchronizes the received waveform using a time-domain copy of the complex Chirp pilot signal. After successful synchronization, a time delay estimate is obtained. Based on this time delay estimate, the target distance estimate is derived. The received waveform is then truncated based on the synchronization result and Doppler compensation is performed to obtain the sound pressure channel and vibration velocity. Channel and vibration velocity OFDM-Chirp passband receive signal of the channel;

[0070] The receiver uses a time-domain copy waveform of the complex Chirp pilot signal to simultaneously measure the sound pressure channel and vibration velocity of the single-vector hydrophone. Channel and vibration velocity The output signal of the channel is copied and correlated in real time to obtain the copy correlation waveform; when a correlation peak that is significantly higher than the background level is found in the output signal of the single-vector hydrophone, the first correlation peak that exceeds the maximum value of the current copy correlation waveform by K times is selected as the synchronization head position; the value of K is between 0.707 and 0.9;

[0071] Step 7: Perform OFDM demodulation on the OFDM-Chirp passband received signal of the sound pressure channel to obtain the decoded bit stream and realize the communication function;

[0072] For sound pressure channels and vibration velocity Channel and vibration velocity The OFDM-Chirp passband received signal of the channel is sequentially down-converted, cyclic prefix (CP) removed, fast Fourier transformed, and downsampled to obtain the OFDM-Chirp baseband received signal;

[0073] The receiver pilot information is extracted from the OFDM-Chirp baseband received signal using a uniform comb-shaped pilot index matrix and then modulated twice to obtain the sound pressure channel and vibration velocity. Channel and vibration velocity The receiving end of the channel receives the Chirp pilot signal;

[0074] Step 7.1: Determine the location of the receiving pilot information based on the uniform comb pilot index matrix, then determine the receiving pilot information based on the location of the receiving pilot information and extract the information from the OFDM-Chirp baseband received signal;

[0075] Step 7.2: Arrange the extracted receiver pilot information in its original order on a one-dimensional empty matrix with a length equal to the number of OFDM baseband signal pilots to obtain the receiver pilot information matrix;

[0076] Step 7.3: Perform secondary modulation on the pilot information matrix at the receiving end to obtain the sound pressure channel and vibration velocity. Channel and vibration velocity The receiving end of the channel receives the Chirp pilot signal;

[0077] Step 8: Based on the sound pressure channel and vibration velocity Channel and vibration velocity The receiving end of the channel uses complex Chirp pilot signals to perform single-vector hydrophone target azimuth estimation using the acoustic energy flow method. Combined with the target distance estimation results, the sensing function is realized.

[0078] Calculate sound pressure signal With vibration velocity signal , mutual spectrum;

[0079]

[0080]

[0081] in, Indicates Fourier transform, Indicates conjugate, the azimuth of the incoming wave of the target. Calculate using the following formula:

[0082]

[0083] It is the arctangent function in the fourth quadrant. This indicates taking the real part.

[0084] To further illustrate the characteristics of the hybrid waveform, simulation experiments were designed, such as... Figure 1 The image shows the LOFAR spectrum of the OFDM-Chirp signal, where the Chirp signal is periodically embedded into the OFDM waveform. Figure 2 BER curves were simulated under different SNRs. At the corresponding SNR, the bit error rate of OFDM-Chirp was close to that of traditional OFDM, indicating that the embedding of Chirp does not affect communication performance. Figures 3 to 5 Chirp's autocorrelation characteristics have a significant advantage over traditional QPSK mapping pilots, thus the hybrid waveform has a better channel estimation capability.

[0085] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for integrating OFDM-Chirp waveform modulation and dual-function implementation of a single-vector hydrophone, characterized in that: The transmitter performs OFDM modulation based on the transmission information and the parameters of the transmitted OFDM baseband signal to obtain a data subcarrier information matrix and a data subcarrier information matrix with added empty carriers. Based on the transmitted OFDM baseband signal parameters, it determines a uniform comb pilot index matrix, a data subcarrier index matrix with added empty carriers, and a complex chirp signal pilot information matrix. According to the index positions given by the uniform comb pilot index matrix, the complex chirp signal pilot information matrix is ​​concatenated with the data subcarrier information matrix with added empty carriers to obtain an OFDM-Chirp hybrid waveform baseband signal. OFDM modulation is then performed on the OFDM-Chirp hybrid waveform baseband signal to obtain an OFDM-Chirp hybrid waveform passband signal. This OFDM-Chirp hybrid waveform passband signal is then transmitted via the transmitter. The complex chirp signal pilot information matrix is ​​then modulated a second time to obtain a time-domain copy waveform of the complex chirp pilot signal, which is then loaded onto the receiver. The receiver receives signals through a single-vector hydrophone. It synchronizes the received waveform using a time-domain copy of the complex Chirp pilot signal. Upon successful synchronization, a time delay estimate is obtained. Based on this time delay estimate, the target distance estimate is derived. The received waveform is truncated based on the synchronization result and Doppler compensation is performed to obtain the OFDM-Chirp passband received signals for the sound pressure and vibration velocity channels. OFDM demodulation is applied to the OFDM-Chirp passband received signal for the sound pressure channel to obtain a decoded bitstream, enabling communication. OFDM demodulation is also performed on the OFDM-Chirp passband received signals for both the sound pressure and vibration velocity channels to obtain the OFDM-Chirp baseband received signal. A uniform comb-shaped pilot index matrix is ​​used to extract the receiver pilot information from the OFDM-Chirp baseband received signal and performs secondary modulation to obtain the receiver complex Chirp pilot signals for the sound pressure and vibration velocity channels. The acoustic energy flow method is then used to estimate the target azimuth of the single-vector hydrophone. Combined with the target distance estimate, the sensing function is achieved.

2. The method for integrating OFDM-Chirp waveform modulation and dual-function implementation of a single-vector hydrophone according to claim 1, characterized in that: The transmitting end performs OFDM modulation based on the transmission information and the transmitted OFDM baseband signal parameters to obtain a data subcarrier information matrix and a data subcarrier information matrix with added empty carriers, specifically: The transmitter generates a transmit bit stream sequence based on the transmit information, and performs channel coding, interleaving, and QPSK mapping on the transmit bit stream sequence in sequence to obtain the data subcarrier information matrix. A null carrier is generated based on the transmitted OFDM baseband signal parameters. The first half of the null carrier is integrated into the front of the data subcarrier information matrix, and the second half of the null carrier is integrated into the back of the data subcarrier information matrix, resulting in a data subcarrier information matrix with the null carrier added.

3. The method for integrating OFDM-Chirp waveform modulation and dual-function implementation of a single-vector hydrophone according to claim 1, characterized in that: The determination of the complex chirp signal pilot information matrix based on the transmitted OFDM baseband signal parameters is specifically as follows: The parameters for transmitting OFDM baseband signals include the OFDM baseband signal pilot spacing. OFDM baseband signal pilot number OFDM baseband signal subcarrier spacing OFDM baseband signal oversampling rate ; Construct the complex chirp signal spectrum based on the transmitted OFDM baseband signal parameters: in, For frequency index, ; This represents the initial number of sampling points for the complex Chirp signal. ; For the oversampling rate of the complex Chirp signal, ; The frequency modulation slope of the complex Chirp signal. ; For the bandwidth of the complex Chirp signal, ; The sampling rate of the complex Chirp signal, ; It is the symbol for imaginary numbers; The spectrum of the complex Chirp signal is truncated, with the truncated interval being the point corresponding to the start frequency of frequency modulation and the point corresponding to the end frequency of frequency modulation, to obtain the pilot information matrix of the complex Chirp signal.

4. The method for integrating OFDM-Chirp waveform modulation and dual-function implementation of a single-vector hydrophone according to claim 1, characterized in that: The process of performing OFDM modulation on the OFDM-Chirp hybrid waveform baseband signal to obtain the OFDM-Chirp hybrid waveform passband signal is as follows: The OFDM-Chirp hybrid waveform baseband signal is sequentially upsampled, subjected to inverse fast Fourier transform, upconverted and real part extracted, cyclic prefix CP is added, and peak-to-average ratio suppression is performed to obtain the OFDM-Chirp hybrid waveform passband signal.

5. The method for integrating OFDM-Chirp waveform modulation and dual-function implementation of a single-vector hydrophone according to claim 1, characterized in that: The vibration velocity channel includes vibration velocity. Channel and vibration velocity aisle; The receiving end receives signals through a single-vector hydrophone and synchronizes the received waveform using a time-domain copy waveform of the complex Chirp pilot signal, specifically as follows: The receiver uses a time-domain copy waveform of the complex Chirp pilot signal to simultaneously measure the sound pressure channel and vibration velocity of the single-vector hydrophone. Channel and vibration velocity The output signal of the channel is subjected to real-time copy correlation to obtain the copy correlation waveform; When a correlation peak significantly higher than the background level is found in the output signal of a single-vector hydrophone, the first correlation peak that exceeds the maximum value of the current copy correlation waveform by K times is selected as the synchronization head position; the value of K is between 0.707 and 0.

9.

6. The method for integrating OFDM-Chirp waveform modulation and dual-function implementation of a single-vector hydrophone according to claim 5, characterized in that: The OFDM-Chirp passband received signals from the sound pressure channel and vibration velocity channel are demodulated using OFDM to obtain the OFDM-Chirp baseband received signals, specifically as follows: For sound pressure channels and vibration velocity Channel and vibration velocity The OFDM-Chirp passband received signal of the channel is sequentially down-converted, cyclic prefix (CP) removed, fast Fourier transformed, and downsampled to obtain the OFDM-Chirp baseband received signal; The process involves extracting receiver pilot information from the OFDM-Chirp baseband received signal using a uniform comb-shaped pilot index matrix and performing secondary modulation to obtain the receiver complex Chirp pilot signals for the sound pressure channel and vibration velocity channel. Specifically: The location of the receiver pilot information is determined by the uniform comb pilot index matrix, and then the receiver pilot information is determined by the location of the receiver pilot information and extracted from the OFDM-Chirp baseband received signal. The extracted pilot information from the receiving end is arranged in its original order on a one-dimensional empty matrix with a length equal to the number of pilot signals of the OFDM baseband signal, thus obtaining the pilot information matrix from the receiving end. The pilot information matrix at the receiving end is modulated twice to obtain the sound pressure channel and vibration velocity. Channel and vibration velocity The receiving end of the channel receives the Chirp pilot signal.

7. The method for integrating OFDM-Chirp waveform modulation and dual-function implementation of a single-vector hydrophone according to claim 6, characterized in that: The secondary modulation includes upsampling, inverse fast Fourier transform, and upconversion; The secondary modulation of the complex Chirp signal pilot information matrix is ​​specifically as follows: The pilot information matrix of the complex Chirp signal is upsampled to obtain the upsampled pilot frequency domain signal of the complex Chirp signal; the upsampled pilot frequency domain signal of the complex Chirp signal is then subjected to inverse fast Fourier transform and upconversion to obtain the time domain copy waveform of the complex Chirp pilot signal. The secondary modulation of the pilot information matrix at the receiving end is specifically as follows: The receiver pilot information matrix is ​​upsampled to obtain the upsampled receiver pilot frequency domain signal; the upsampled receiver pilot frequency domain signal is then subjected to inverse fast Fourier transform and upconversion to obtain the sound pressure channel and vibration velocity. Channel and vibration velocity The receiving end of the channel receives the Chirp pilot signal.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When executed by a processor, the computer program implements the steps of the method according to any one of claims 1 to 7.

10. A computer program product comprising computer instructions, characterized in that: When executed by a processor, the computer instructions implement the steps of the method according to any one of claims 1 to 7.

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