Remote acoustic signal pickup method and system based on phase-encoded microwave sensing

Abstract

The application provides a remote acoustic signal pickup method and system based on phase coding microwave sensing, comprising: constructing a phase coding matrix, and performing phase shift control on the transmission signals of multiple transmission antennas; controlling the multiple transmission antennas to simultaneously transmit a linear frequency modulation continuous wave signal, so that the main lobe of a synthesized beam is directed towards the direction of a to-be-detected acoustic source or the direction of a target medium; using one or more receiving antennas to receive echo signals of the acoustic source target, to obtain a corresponding number of baseband signals; performing acoustic vibration phase demodulation on the corresponding number of baseband signals, to extract vibration information of the surface of the medium target caused by the vibration information of the acoustic source or caused by the excitation of the acoustic wave; and reconstructing the acoustic signal, to realize remote acoustic pickup. The application overcomes the problems of weak echo signals, low signal-to-noise ratio, large adjacent target interference and low quality of reconstructed acoustic signals in remote acoustic pickup, and improves the signal-to-noise ratio and sensing distance of remote acoustic pickup.

Description

Technical Field

[0001] This invention relates to the field of sound pickup technology, and more specifically, to a method and system for remote sound signal pickup based on phase-coded microwave sensing. Background Technology

[0002] Sound, as a crucial means and medium for communication and interaction, has always been a focus of research in the field of information security. Most existing sound pickup methods involve recording with microphones such as mobile phones, voice recorders, and microphones. However, these devices have significant drawbacks in terms of security, concealment, and convenience. Furthermore, this type of microphone sensing technology converts sound signals into electrical signals, which are then amplified and converted from analog to digital for storage. During transmission, these signals are easily affected by various shielding devices, interfering with the transmission process.

[0003] Patent document CN110568073A (application number: CN201910871148.5) discloses a method for picking up impact signals in a noisy environment. The method includes: step S1: acquiring the sound frequency signal of the tunnel lining by impact, and recording it as the sampling signal; step S2: extracting and separating the impact signal and noise signal from the sampling signal by short-time Fourier transform analysis based on the sampling signal obtained in step S1, thereby extracting the excitation signal, wherein the signal before the impact signal position is the noise signal; step S3: performing Hamming window filtering and FFT spectrum analysis on both the excitation signal and the noise signal extracted in step S2, subtracting the noise signal spectrum from the effective signal interval spectrum to obtain the true excitation signal spectrum; at the same time, analyzing the dominant period and centroid period of the true excitation signal spectrum to perform impact detection defect analysis.

[0004] Existing long-range non-contact sound pickup methods mainly include laser, vision, and microwave methods. Laser interferometry-based sound sensing technology can achieve long-distance sound pickup, but it primarily focuses on single-point testing and requires high surface quality from the target object, making it very demanding. Vision-based sound sensing technology is limited by camera frame rate, primarily tests low-frequency sounds, and is significantly affected by environmental factors such as lighting, resulting in lower accuracy. Microwave-based sound pickup technology can achieve high-quality sound perception, but as the transmission distance increases, the echo signal weakens, the signal-to-noise ratio decreases, and long-range sound perception is limited. Therefore, researching highly reliable long-range sound pickup technologies is of great significance for sound sensing and information security.

[0005] Existing microwave-based sound sensing methods suffer from weak echo signals, reduced signal-to-noise ratio, and severe interference from nearby target coupling clutter in remote sound pickup, which seriously affects the accuracy of sound signal reconstruction. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method and system for remote acoustic signal acquisition based on phase-coded microwave sensing.

[0007] The remote acoustic signal pickup method based on phase-coded microwave sensing provided by the present invention includes:

[0008] Step S1: Construct a phase coding matrix to perform phase shift control on the transmitted signals from multiple transmit antennas;

[0009] Step S2: Control multiple transmitting antennas to simultaneously transmit linear frequency modulated continuous wave signals, so that the main lobe of the synthesized beam is oriented towards the direction of the sound source to be tested or the target medium, and use one or more receiving antennas to receive the echo signals of the sound source target to obtain the baseband signals of the corresponding number of channels;

[0010] Step S3: Perform acoustic phase demodulation on the baseband signals of the corresponding number of channels to extract the vibration information of the target medium surface caused by the vibration of the sound source or by the excitation of the sound wave;

[0011] Step S4: Reconstruct the sound signal to achieve remote sound pickup.

[0012] Preferably, step S1 includes:

[0013] Let θ1 be the angle between the location of the sound source or target medium and the transmitting antenna array. Construct the phase encoding matrix:

[0014]

[0015] Where, d k λ represents the distance between the k-th transmitting antenna and the first transmitting antenna; K is the number of transmitting antennas; k = 2, ..., K; c The wavelength corresponding to the center frequency of a linear frequency modulated continuous wave;

[0016] Based on the phase coding matrix, the initial phase of each transmit antenna is set as follows: 0, 2πd²sinθ¹ / λ c , …, 2πd K sinθ1 / λ c The system controls each antenna to transmit microwave signals simultaneously, so that the main lobe of the synthesized beam is θ1 and is directed toward the sound source or target medium to be measured.

[0017] Let the transmitted signal from the first transmitting antenna be s1(t), and the synthesized transmitted signal through phase shift control be:

[0018]

[0019] in,

[0020]

[0021]

[0022]

[0023] A T Let f be the amplitude of the transmitted signal, f0 be the initial frequency of the transmitted signal, B be the signal bandwidth, T be the time length of one sweep cycle of the transmitted signal, φ0 be the initial phase, t be the time series, θ be the traversal angle, and a(θ) be the amplitude of the transmitted signal. H d is the conjugate transpose of a(θ); d is the spacing between each transmitting antenna.

[0024] Preferably, step S2 includes:

[0025] Multiple transmitting antennas are controlled to simultaneously transmit linear frequency modulated continuous wave signals, so that the main lobe of the synthesized beam is oriented towards the direction of the sound source or the target medium. One or more receiving antennas are used to receive the echo signals from the sound source / target. After hardware mixing and low-pass filtering, the baseband signal corresponding to the channel of the first receiving antenna is obtained as follows:

[0026]

[0027] In the formula, ψ=πd(sinθ0-sinθ) / λ c

[0028] set up After demodulation using the beat frequency, the complex phase vector is obtained, which is expressed as:

[0029]

[0030] The complex phase vector of the receiving array antenna channel is expressed as:

[0031]

[0032] Among them, A B The amplitude of the received signal is T, where λ0 is the wavelength corresponding to the initial frequency. sweep The sweep frequency is the time duration; R is the distance between the target and the antenna; c is the speed of light; x(iT) sweep ) represents the displacement value within the i-th sweep frequency cycle; ψ is an intermediate quantity; f b This refers to the beat frequency; This represents phase information related to the distance from the target to the microwave transceiver; This represents the phase change value caused by the target vibration during the i-th frequency sweep cycle.

[0033] Preferably, step S3 includes:

[0034] By demodulating the acoustic phase, the vibration displacement sequence of the target sound source or target medium surface in each scanning cycle is extracted:

[0035]

[0036] In the formula, x(p,θ) s ,R,iT sweep ) represents the p-th cyclic scan, with the beam scanning angle being θ. s 1. Displacement sequence element values ​​of the target or measuring point under test with a transmission sweep period of i and a current scanning angle distance of R; arg{} is the operation for taking complex phase values; N is the number of single-channel baseband signal elements in each sweep period; n is the sequence number of single-channel baseband signal elements in each sweep period; T s The sampling frequency and time of the baseband signal; s B (p,θ s iT,nT s ) represents the p-th cyclic scan, with a beam scanning angle of θ. s The matrix consists of M baseband signals from the i-th transmit frequency sweep cycle, with column vectors representing the baseband signals from the m-th channels (m = 1, 2, ..., M); j is the imaginary unit. The estimated beat frequency corresponding to the distance between the measured target or measuring point; d rxm Let d be the distance from the m-th receiving antenna to the first receiving antenna, where m = 1, ..., M, and d is the distance from the m-th receiving antenna to the first receiving antenna. rx1 =0.

[0037] Preferably, step S4 includes: processing the extracted vibration signal of the sound source or target medium surface using methods including low-pass filtering to obtain a sound signal within the sound frequency band, thereby achieving remote sound pickup. If multiple sound source targets exist, steps S1-S3 are repeated, based on the azimuth angle θ of the remaining sound sources. i A phase encoding matrix is ​​constructed, and the acoustic vibration signal of the sound source is extracted to achieve remote sound pickup.

[0038] The remote acoustic signal pickup system based on phase-coded microwave sensing provided by the present invention includes:

[0039] Module M1: Constructs a phase coding matrix to perform phase shift control on the transmitted signals from multiple transmit antennas;

[0040] Module M2: Controls multiple transmitting antennas to simultaneously transmit linear frequency modulated continuous wave signals, so that the main lobe of the synthesized beam is oriented towards the direction of the sound source under test or the target medium, and uses one or more receiving antennas to receive the echo signals of the sound source target to obtain the baseband signals of the corresponding number of channels;

[0041] Module M3: Performs acoustic phase demodulation on the baseband signals of the corresponding number of channels to extract vibration information of the target medium surface caused by the vibration of the sound source or by the excitation of the sound wave;

[0042] Module M4: Reconstructs the audio signal to enable remote audio pickup.

[0043] Preferably, the module M1 includes:

[0044] Let θ1 be the angle between the location of the sound source or target medium and the transmitting antenna array. Construct the phase encoding matrix:

[0045]

[0046] Where, d k λ represents the distance between the k-th transmitting antenna and the first transmitting antenna; K is the number of transmitting antennas; k = 2, ..., K; c The wavelength corresponding to the center frequency of a linear frequency modulated continuous wave;

[0047] Based on the phase coding matrix, the initial phase of each transmit antenna is set as follows: 0, 2πd²sinθ¹ / λ c , …, 2πd K sinθ1 / λ c The system controls each antenna to transmit microwave signals simultaneously, so that the main lobe of the synthesized beam is θ1 and is directed toward the sound source or target medium to be measured.

[0048] Let the transmitted signal from the first transmitting antenna be s1(t), and the synthesized transmitted signal through phase shift control be:

[0049]

[0050] in,

[0051]

[0052]

[0053]

[0054] A T Let f be the amplitude of the transmitted signal, f0 be the initial frequency of the transmitted signal, B be the signal bandwidth, T be the time length of one sweep cycle of the transmitted signal, φ0 be the initial phase, t be the time series, θ be the traversal angle, and a(θ) be the amplitude of the transmitted signal. H d is the conjugate transpose of a(θ); d is the spacing between each transmitting antenna.

[0055] Preferably, the module M2 includes:

[0056] Multiple transmitting antennas are controlled to simultaneously transmit linear frequency modulated continuous wave signals, so that the main lobe of the synthesized beam is oriented towards the direction of the sound source or the target medium. One or more receiving antennas are used to receive the echo signals from the sound source / target. After hardware mixing and low-pass filtering, the baseband signal corresponding to the channel of the first receiving antenna is obtained as follows:

[0057]

[0058] In the formula, ψ=πd(sinθ0-sinθ) / λ c

[0059] set up After demodulation using the beat frequency, the complex phase vector is obtained, which is expressed as:

[0060]

[0061] The complex phase vector of the receiving array antenna channel is expressed as:

[0062]

[0063] Among them, A B The amplitude of the received signal is T, where λ0 is the wavelength corresponding to the initial frequency. sweep The sweep frequency is the time duration; R is the distance between the target and the antenna; c is the speed of light; x(iT) sweep ) represents the displacement value within the i-th sweep frequency cycle; ψ is an intermediate quantity; f b This refers to the beat frequency; This represents phase information related to the distance from the target to the microwave transceiver; This represents the phase change value caused by the target vibration during the i-th frequency sweep cycle.

[0064] Preferably, the module M3 includes:

[0065] By demodulating the acoustic phase, the vibration displacement sequence of the target sound source or target medium surface in each scanning cycle is extracted:

[0066]

[0067] In the formula, x(p,θ) s ,R,iT sweep ) represents the p-th cyclic scan, with the beam scanning angle being θ. s 1. Displacement sequence element values ​​of the target or measuring point under test with a transmission sweep period of i and a current scanning angle distance of R; arg{} is the operation for taking complex phase values; N is the number of single-channel baseband signal elements in each sweep period; n is the sequence number of single-channel baseband signal elements in each sweep period; T s The sampling frequency and time of the baseband signal; s B(p,θ s iT,nT s ) represents the p-th cyclic scan, with a beam scanning angle of θ. s The matrix consists of M baseband signals from the i-th transmit frequency sweep cycle, with column vectors representing the baseband signals from the m-th channels (m = 1, 2, ..., M); j is the imaginary unit. The estimated beat frequency corresponding to the distance between the measured target or measuring point; d rxm Let d be the distance from the m-th receiving antenna to the first receiving antenna, where m = 1, ..., M, and d is the distance from the m-th receiving antenna to the first receiving antenna. rx1 =0.

[0068] Preferably, module M4 includes: processing the extracted vibration signal of the sound source or target medium surface through methods including low-pass filtering to obtain a sound signal within the sound frequency range, thereby achieving remote sound pickup; if there are multiple sound source targets, modules M1-M3 are repeatedly executed, based on the azimuth angle θ of the remaining sound sources. i A phase encoding matrix is ​​constructed, and the acoustic vibration signal of the sound source is extracted to achieve remote sound pickup.

[0069] Compared with the prior art, the present invention has the following beneficial effects:

[0070] The remote sound pickup method based on phase-coded microwave sensing proposed in this invention overcomes the problems of weak echo signals, low signal-to-noise ratio, large interference from nearby targets, and low quality of reconstructed sound signals in existing microwave sensing methods for remote sound pickup, thereby improving the signal-to-noise ratio and sensing distance of remote sound pickup. Attached Figure Description

[0071] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0072] Figure 1 This is a flowchart of the remote sound pickup method based on phase-coded microwave sensing of the present invention;

[0073] Figure 2a and Figure 2b This is a schematic diagram of the antenna beam for achieving synthetic beam focusing through phase control according to the present invention;

[0074] Figure 3 This is a schematic diagram illustrating remote sound pickup in a multi-sound-source scenario according to the present invention. Detailed Implementation

[0075] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0076] Example 1:

[0077] like Figure 1 The diagram shows a flowchart of the remote sound pickup method based on phase-coded microwave sensing proposed in this invention. Specifically, the method involves: First, constructing a phase-coding matrix to control the phase shift of the transmitted signals from multiple transmitting antennas; controlling multiple transmitting antennas to simultaneously transmit linear frequency modulated continuous wave signals, ensuring the main lobe of the synthesized beam faces the direction of the sound source or the target medium; using one or more receiving antennas to receive the echo signals from the sound source target, obtaining baseband signals with the corresponding number of channels; then, performing acoustic vibration phase demodulation on the baseband signals with the corresponding number of channels in a distance-angle two-dimensional plane to extract vibration information from the sound source or the vibration information of the target medium surface caused by acoustic wave excitation; finally, reconstructing the sound signal to achieve remote sound pickup.

[0078] Step S1: Construct a phase coding matrix to perform phase shift control on the transmitted signals from multiple transmit antennas.

[0079] This invention reconstructs sound signals by measuring the vibration of a sound source or the vibration of surrounding environmental targets caused by sound using a microwave sensing method. To achieve long-range sound pickup and improve the signal-to-noise ratio of the echo signal, phase coding and phase shift control are used to focus the synthesized beam of multiple transmitted and received microwave signals in one direction, thereby increasing the sensing distance and the echo signal-to-noise ratio.

[0080] Assuming the angle between the location of the sound source or target medium and the transmitting antenna array is θ1, construct the phase coding matrix:

[0081]

[0082] Where, d k λ represents the distance between the k-th transmitting antenna and the first transmitting antenna; K is the number of transmitting antennas; k = 2, ..., K; c The wavelength corresponding to the center frequency of a linear frequency modulated continuous wave;

[0083] Based on the phase coding matrix, the initial phase of each transmit antenna is set as follows: 0, 2πd²sinθ¹ / λ c , …, 2πd K sinθ1 / λ c To control each antenna to transmit microwave signals simultaneously, such as Figure 2a and Figure 2b As shown, the main lobe direction angle of the synthesized beam is set to θ1, pointing towards the sound source or target medium to be measured. The sensing distance after beam synthesis is increased by 2-3 times compared with that before beam synthesis.

[0084] Let the transmitted signal from the first transmitting antenna be s1(t), and the synthesized transmitted signal through phase shift control be:

[0085]

[0086] in,

[0087]

[0088]

[0089]

[0090] A T Let f be the amplitude of the transmitted signal, f0 be the initial frequency of the transmitted signal, B be the signal bandwidth, T be the time length of one sweep cycle of the transmitted signal, φ0 be the initial phase, t be the time series, θ be the traversal angle, and a(θ) be the amplitude of the transmitted signal. H d is the conjugate transpose of a(θ); d is the spacing between each transmitting antenna.

[0091] Step S2: Transmit and receive linear frequency modulated continuous wave signals to obtain multi-channel baseband signals.

[0092] Multiple transmitting antennas are controlled to simultaneously transmit linear frequency modulated continuous wave signals, so that the main lobe of the synthesized beam is oriented towards the direction of the sound source or the target medium. One or more receiving antennas are used to receive the echo signals from the sound source / target. After hardware mixing and low-pass filtering, the baseband signal corresponding to the channel of the first receiving antenna is obtained as follows:

[0093]

[0094] In the formula, ψ=πd(sinθ0-sinθ) / λ c

[0095] set up After demodulation by the beat frequency, the complex phase vector is obtained as follows: The complex phase vector of the receiving array antenna channel can be expressed as:

[0096]

[0097] Among them, A B The amplitude of the received signal is T, where λ0 is the wavelength corresponding to the initial frequency. sweep The sweep frequency is the time duration; R is the distance between the target and the antenna; c is the speed of light; x(iT) sweep) represents the displacement value within the i-th sweep frequency cycle; ψ is an intermediate quantity; f b This refers to the beat frequency; This represents phase information related to the distance from the target to the microwave transceiver; This represents the phase change value caused by the target vibration during the i-th frequency sweep cycle;

[0098] As can be seen, when θ = θ0, the amplitude is that of a single transmitting antenna. The power is times that of a single transmitting antenna (K). 2 The beamforming and focusing vibration measurement mechanism and method significantly improve the signal strength radiated to the target, thereby greatly increasing the signal-to-noise ratio of the target vibration measurement and effectively reducing noise interference. This provides an effective method for solving the problem of measuring the vibration of remote sound sources or the vibration of media excited by sound waves, thus overcoming the challenge of remote sound signal pickup.

[0099] Step S3: Sound and vibration phase demodulation to extract vibration information of the sound source or target medium surface under test.

[0100] By demodulating the acoustic phase, the vibration displacement sequence of the target sound source or target medium surface in each scanning cycle is extracted:

[0101]

[0102] In the formula, x(p,θ) s ,R,iT sweep ) represents the p-th cyclic scan, with the beam scanning angle being θ. s 1. Displacement sequence element values ​​of the target or measuring point under test with a transmission sweep period of i and a current scanning angle distance of R; arg{} is the operation for taking complex phase values; N is the number of single-channel baseband signal elements in each sweep period; n is the sequence number of single-channel baseband signal elements in each sweep period; T s The sampling frequency and time of the baseband signal; s B (p,θ s iT,nT s ) represents the p-th cyclic scan, with a beam scanning angle of θ. s The matrix consists of M baseband signals from the i-th transmit frequency sweep cycle, with column vectors representing the baseband signals from the m-th channels (m = 1, 2, ..., M); j is the imaginary unit. The estimated beat frequency corresponding to the distance between the measured target or measuring point; d rxm Let d be the distance from the m-th receiving antenna to the first receiving antenna, where m = 1, ..., M, and d is the distance from the m-th receiving antenna to the first receiving antenna. rx1 =0;

[0103] Step S4: Reconstruct the sound signal to achieve remote sound pickup.

[0104] The vibration signal extracted from the sound source or target medium surface is processed using methods including low-pass filtering to obtain an acoustic signal within a specific frequency range, enabling remote sound pickup. In practical applications, the processed vibration signal can be normalized.

[0105] If there are multiple sound source targets, such as Figure 3 The test scenario diagram shown is repeated using steps S1-S3, based on the azimuth angle θ of the remaining sound sources. i A phase encoding matrix is ​​constructed, and the acoustic vibration signal of the sound source is extracted to achieve remote sound pickup.

[0106] Example 2:

[0107] The present invention also provides a remote acoustic signal pickup system based on phase-coded microwave sensing. The remote acoustic signal pickup system based on phase-coded microwave sensing can be implemented by executing the process steps of the remote acoustic signal pickup method based on phase-coded microwave sensing. That is, those skilled in the art can understand the remote acoustic signal pickup method based on phase-coded microwave sensing as a preferred embodiment of the remote acoustic signal pickup system based on phase-coded microwave sensing.

[0108] The remote acoustic signal pickup system based on phase-coded microwave sensing provided by the present invention includes: module M1: constructing a phase coding matrix and performing phase shift control on the transmitted signals of multiple transmitting antennas; module M2: controlling multiple transmitting antennas to simultaneously transmit linear frequency modulated continuous wave signals, such that the main lobe of the synthesized beam is oriented towards the direction of the sound source to be measured or the direction of the target medium, and using one or more receiving antennas to receive the echo signals of the sound source target to obtain the baseband signals of the corresponding number of channels; module M3: performing acoustic vibration phase demodulation on the baseband signals of the corresponding number of channels to extract the vibration information of the sound source or the vibration information of the target medium surface caused by acoustic wave excitation; module M4: reconstructing the sound signal to realize remote sound pickup.

[0109] The module M1 includes: setting the angle of the location of the sound source or target medium relative to the transmitting antenna array as θ1, and constructing a phase encoding matrix:

[0110]

[0111] Where, d k λ represents the distance between the k-th transmitting antenna and the first transmitting antenna; K is the number of transmitting antennas; k = 2, ..., K; c The wavelength corresponding to the center frequency of a linear frequency modulated continuous wave;

[0112] Based on the phase coding matrix, the initial phase of each transmit antenna is set as follows: 0, 2πd²sinθ¹ / λ c , …, 2πdK sinθ1 / λ c The system controls each antenna to transmit microwave signals simultaneously, so that the main lobe of the synthesized beam is θ1 and is directed toward the sound source or target medium to be measured.

[0113] Let the transmitted signal from the first transmitting antenna be s1(t), and the synthesized transmitted signal through phase shift control be:

[0114]

[0115] in,

[0116]

[0117]

[0118]

[0119] A T Let f be the amplitude of the transmitted signal, f0 be the initial frequency of the transmitted signal, B be the signal bandwidth, T be the time length of one sweep cycle of the transmitted signal, φ0 be the initial phase, t be the time series, θ be the traversal angle, and a(θ) be the amplitude of the transmitted signal. H d is the conjugate transpose of a(θ); d is the spacing between each transmitting antenna.

[0120] The module M2 includes: controlling multiple transmitting antennas to simultaneously transmit linear frequency modulated continuous wave signals, such that the main lobe of the synthesized beam is oriented towards the direction of the sound source or the target medium; using one or more receiving antennas to receive the echo signal from the sound source target; and obtaining the baseband signal of the channel corresponding to the first receiving antenna after hardware mixing and low-pass filtering.

[0121]

[0122] In the formula, ψ=πd(sinθ0-sinθ) / λ c

[0123] set up After demodulation using the beat frequency, the complex phase vector is obtained, which is expressed as:

[0124]

[0125] The complex phase vector of the receiving array antenna channel is expressed as:

[0126]

[0127] Among them, A B The amplitude of the received signal is T, where λ0 is the wavelength corresponding to the initial frequency. sweepThe sweep frequency is the time duration; R is the distance between the target and the antenna; c is the speed of light; x(iT) sweep ) represents the displacement value within the i-th sweep frequency cycle; ψ is an intermediate quantity; f b This refers to the beat frequency; This represents phase information related to the distance from the target to the microwave transceiver; This represents the phase change value caused by the target vibration during the i-th frequency sweep cycle.

[0128] The module M3 includes: extracting the vibration displacement sequence of the expected sound source or target medium surface for each scanning cycle through acoustic phase demodulation.

[0129]

[0130] In the formula, x(p,θ) s ,R,iT sweep ) represents the p-th cyclic scan, with the beam scanning angle being θ. s 1. Displacement sequence element values ​​of the target or measuring point under test with a transmission sweep period of i and a current scanning angle distance of R; arg{} is the operation for taking complex phase values; N is the number of single-channel baseband signal elements in each sweep period; n is the sequence number of single-channel baseband signal elements in each sweep period; T s The sampling frequency and time of the baseband signal; s B (p,θ s iT,nT s ) represents the p-th cyclic scan, with a beam scanning angle of θ. s The matrix consists of M baseband signals from the i-th transmit frequency sweep cycle, with column vectors representing the baseband signals from the m-th channels (m = 1, 2, ..., M); j is the imaginary unit. The estimated beat frequency corresponding to the distance between the measured target or measuring point; d rxm Let d be the distance from the m-th receiving antenna to the first receiving antenna, where m = 1, ..., M, and d is the distance from the m-th receiving antenna to the first receiving antenna. rx1 =0.

[0131] Module M4 includes: processing the extracted vibration signal from the surface of the sound source or target medium using methods including low-pass filtering to obtain a sound signal within the sound frequency range, thereby achieving remote sound pickup. If multiple sound source targets exist, modules M1-M3 are executed repeatedly, based on the azimuth angle θ of the remaining sound sources. i A phase encoding matrix is ​​constructed, and the acoustic vibration signal of the sound source is extracted to achieve remote sound pickup.

[0132] Those skilled in the art will understand that, in addition to implementing the system, apparatus, and their modules provided by this invention in purely computer-readable program code, the same program can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system, apparatus, and their modules provided by this invention can be considered a hardware component, and the modules included therein for implementing various programs can also be considered structures within the hardware component; alternatively, modules for implementing various functions can be considered both software programs implementing the method and structures within the hardware component.

[0133] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for long-range acoustic signal pickup based on phase-coded microwave sensing, characterized in that, include: Step S1: Construct a phase coding matrix to perform phase shift control on the transmitted signals from multiple transmit antennas; Step S2: Control multiple transmitting antennas to simultaneously transmit linear frequency modulated continuous wave signals, so that the main lobe of the synthesized beam is oriented towards the direction of the sound source to be tested or the target medium, and use one or more receiving antennas to receive the echo signals of the sound source target to obtain the baseband signals of the corresponding number of channels; Step S3: Perform acoustic phase demodulation on the baseband signals of the corresponding number of channels obtained in step S2 to extract the vibration information of the sound source or the vibration information of the target surface of the medium caused by acoustic excitation; Step S4: Reconstruct the sound signal to achieve remote sound signal pickup.

2. The method for long-range acoustic signal pickup based on phase-coded microwave sensing according to claim 1, characterized in that, Step S1 includes: Let the angle between the location of the sound source or target medium and the transmitting antenna array be θ. Construct the phase encoding matrix: in, Let K be the distance between the k-th transmitting antenna and the first transmitting antenna; K is the number of transmitting antennas; k = 2, ..., K; The wavelength corresponding to the center frequency of a linear frequency modulated continuous wave; Based on the phase coding matrix, the initial phase of each transmit antenna is set as follows: 0, , ..., Controlling each antenna to simultaneously transmit microwave signals, so that the main lobe angle of the synthesized beam is... Oriented toward the sound source or target medium to be tested.

3. The method for long-range acoustic signal acquisition based on phase-coded microwave sensing according to claim 2, characterized in that, Step S2 includes: Multiple transmitting antennas are controlled to simultaneously transmit linear frequency modulated continuous wave signals, so that the main lobe of the synthesized beam is oriented towards the direction of the sound source or the target medium. One or more receiving antennas are used to receive the echo signals of the sound source or target. After hardware mixing and low-pass filtering, a multi-channel microwave baseband signal is obtained.

4. The method for long-range acoustic signal pickup based on phase-coded microwave sensing according to claim 3, characterized in that, Step S3 includes: By demodulating the acoustic phase, the vibration displacement sequence of the target sound source or target medium surface in each scanning cycle is extracted: In the formula, Represented as the first The angles of the secondary cycle scan and beam scan are: The transmission frequency sweep period is The displacement sequence element values ​​of the target or measuring point at the current scanning angle distance of R; The frequency sweep period for transmitting linear frequency modulated continuous waves via the transmitting antenna; For operations involving complex phase values; N is the number of single-channel baseband signal elements in each sweep cycle; n is the index of the single-channel baseband signal element in each sweep cycle; The sampling frequency and time of the baseband signal; For the first The sub-cycle scan and beam scan angle are: , No. A matrix consisting of M channels of baseband signals across 1 transmit sweep cycle, with column vectors of the matrix being the ______. The baseband signal of the channel; The imaginary unit; This is the estimated beat frequency corresponding to the distance between the measured target or the measuring point; The wavelength corresponding to the center frequency of a linear frequency modulated continuous wave; Let be the distances from the m-th receiving antenna to the first receiving antenna, where m = 1, ..., M. .

5. The method for long-range acoustic signal pickup based on phase-coded microwave sensing according to claim 4, characterized in that, Step S4 includes: processing the vibration signal of the sound source or target medium surface under test using methods including low-pass filtering to obtain a sound signal within the sound frequency band range, thereby achieving remote sound pickup. If there are multiple sound source targets, steps S1-S3 are repeated, based on the azimuth angles of the remaining sound sources. A phase encoding matrix is ​​constructed, and the acoustic vibration signal of the sound source is extracted to achieve remote sound pickup.

6. A long-range acoustic signal pickup system based on phase-coded microwave sensing, characterized in that, include: Module M1: Constructs a phase coding matrix to perform phase shift control on the transmitted signals from multiple transmit antennas; Module M2: Controls multiple transmitting antennas to simultaneously transmit linear frequency modulated continuous wave signals, so that the main lobe of the synthesized beam is oriented towards the direction of the sound source under test or the target medium, and uses one or more receiving antennas to receive the echo signals of the sound source target to obtain the baseband signals of the corresponding number of channels; Module M3: Performs acoustic phase demodulation on the baseband signals of the corresponding number of channels obtained by module M2 to extract the vibration information of the sound source or the vibration information of the target surface of the medium caused by acoustic excitation; Module M4: Reconstructs the audio signal to enable remote audio pickup.

7. The remote acoustic signal pickup system based on phase-coded microwave sensing according to claim 6, characterized in that, The module M1 includes: Let the angle between the location of the sound source or target medium and the transmitting antenna array be θ. Construct the phase encoding matrix: in, Let K be the distance between the k-th transmitting antenna and the first transmitting antenna; K is the number of transmitting antennas; k = 2, ..., K; The wavelength corresponding to the center frequency of a linear frequency modulated continuous wave; Based on the phase coding matrix, the initial phase of each transmit antenna is set as follows: 0, , ..., Controlling each antenna to simultaneously transmit microwave signals, so that the main lobe angle of the synthesized beam is... Oriented toward the sound source or target medium to be tested.

8. The remote acoustic signal pickup system based on phase-coded microwave sensing according to claim 7, characterized in that, The module M2 includes: Multiple transmitting antennas are controlled to simultaneously transmit linear frequency modulated continuous wave signals, so that the main lobe of the synthesized beam is oriented towards the direction of the sound source or the target medium. One or more receiving antennas are used to receive the echo signals of the sound source or target. After hardware mixing and low-pass filtering, a multi-channel microwave baseband signal is obtained.

9. The remote acoustic signal pickup system based on phase-coded microwave sensing according to claim 8, characterized in that, The module M3 includes: By demodulating the acoustic phase, the vibration displacement sequence of the target sound source or target medium surface in each scanning cycle is extracted: In the formula, Represented as the first The angles of the secondary cycle scan and beam scan are: The transmission frequency sweep period is The displacement sequence element values ​​of the target or measuring point at the current scanning angle distance of R; For operations involving complex phase values; N is the number of single-channel baseband signal elements in each sweep cycle; n is the index of the single-channel baseband signal element in each sweep cycle; The sampling frequency and time of the baseband signal; For the first The sub-cycle scan and beam scan angle are: , No. A matrix consisting of M channels of baseband signals across 1 transmit sweep cycle, with column vectors of the matrix being the ______. The baseband signal of the channel; The imaginary unit; This is the estimated beat frequency corresponding to the distance between the measured target or the measuring point; Let be the distances from the m-th receiving antenna to the first receiving antenna, where m = 1, ..., M. .

10. The long-range acoustic signal pickup system based on phase-coded microwave sensing according to claim 9, characterized in that, Module M4 includes: processing the vibration signal of the sound source or target medium surface under test through methods including low-pass filtering to obtain the sound signal within the sound frequency range, thereby achieving remote sound pickup; if there are multiple sound source targets, modules M1-M3 are repeatedly executed, based on the azimuth angles of the remaining sound sources. A phase encoding matrix is ​​constructed, and the acoustic vibration signal of the sound source is extracted to achieve remote sound pickup.

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