Active device internal acoustic wave penetration communication system and method

Abstract

The application relates to the field of communication transmission, and discloses an active internal sound wave penetration communication system and method of equipment, the system comprising: a sound signal transmitting circuit, a metal barrier and a sound signal receiving circuit; the sound signal transmitting circuit is arranged on one side of the metal barrier and is used for actively generating a sound signal to excite a resonance signal generated by a metal structure in the metal barrier; the sound signal receiving circuit is arranged on the other side of the metal barrier and is used for receiving the resonance signal and demodulating the resonance signal to obtain communication digital information in the sound emission signal. The method adopts a transmitting end power pre-equalization control and a TRM algorithm for processing to restore original communication digital information. Through key technologies such as resonance excitation, multi-frequency point modulation, cooperative design of a piezoelectric transducer and an LC impedance matching network, and time reversal mirror (TRM) algorithm for suppressing multipath interference, the application realizes high-speed and low-error-rate data penetration communication without damaging the integrity of the metal barrier.

Description

Technical Field

[0001] This invention relates to the field of communication transmission, and more particularly to an active device internal acoustic wave penetration communication system and method. Background Technology

[0002] In industrial settings characterized by strong electromagnetic interference (EMI) and fully sealed metal environments, traditional wireless communication technologies (such as WiFi, Bluetooth, and ZigBee) and wired communications face severe challenges. Common scenarios include: 1. Inside the energy storage battery cabinet: The charging and discharging process of the battery generates strong electromagnetic pulses of >100V / m, which causes the wireless signal to be interrupted; the metal shell (1.5-2mm steel plate) forms a Faraday cage effect, blocking the penetration of radio frequency signals; communication between battery modules relies on shielded wire harnesses, which result in high wiring costs per cabinet and are susceptible to corrosion failure.

[0003] 2. Key nodes in the automotive engine compartment: The operation of the engine / motor generates wideband electromagnetic noise of >200MHz, which interferes with the Controller Area Network (CAN) signal; high temperature environment (>120℃) accelerates the aging of wiring harnesses, and the maintenance cost accounts for 40% of the total vehicle circuit failure; the demand for lightweighting forces the reduction of wiring harness weight, and traditional copper cables account for 30% of the weight of engine compartment wiring.

[0004] 3. Other industrial sealing equipment: High-voltage frequency converter control cabinets, ship engine rooms, etc., have similar metal shielding + strong EMI environments; explosion-proof requirements prohibit opening holes for wiring, and radio signal shielding attenuation >60dB.

[0005] Existing technical solutions often fail to enable effective communication in similar scenarios. Summary of the Invention

[0006] The purpose of this invention is to propose an active device internal acoustic wave penetration communication system and method to solve the technical problem that existing technologies cannot achieve communication in specific closed scenarios.

[0007] Specifically, the present invention provides an active device internal acoustic wave penetration communication system, comprising: Sound signal transmitting circuit, metal barrier and sound signal receiving circuit; The acoustic signal transmitting circuit is deployed on one side of the metal barrier to actively generate acoustic signals and excite the metal structure in the metal barrier to generate resonant signals. An acoustic signal receiving circuit is deployed on the other side of the metal barrier to receive the resonant signal and demodulate it to obtain the communication digital information in the acoustic emission signal; Butyl rubber is used as the contact medium between the acoustic signal transmitting circuit and the metal, and also as the contact medium between the acoustic signal receiving circuit and the metal.

[0008] An active device internal acoustic wave penetration communication method, applied to an active device internal acoustic wave penetration communication system, includes the following steps: S1. The digital source transmits the raw data bit stream, while the modulator uses the transmitter power pre-equalization control method to control the power distribution of the power amplifier in the acoustic signal transmission circuit. S2. The power amplifier amplifies the modulation signal according to the power distribution, drives the piezoelectric transmitter to generate acoustic wave excitation, causing the metal plate to resonate and form a resonant signal. S3. The resonance signal is processed by the TRM processor of the acoustic signal receiving circuit using the TRM algorithm and then demodulated to obtain the original data bit stream.

[0009] The beneficial effects provided by this invention are: 1. Metal barrier broadband transmission technology Core Innovation: Breaking through the narrowband resonance limitation of traditional acoustic communication, the design utilizes a synergistic approach of acoustic coupling layer and LC impedance matching network to improve the metallic resonance quality factor. The signal strength was reduced from 15 to 2.3, and the transmission bandwidth was expanded from 1.87 kHz to 12.2 kHz. A high-transmission plateau region was constructed in the 26–30 kHz band, supporting broadband communication with 12 subcarriers.

[0010] 2. Time-domain anti-multipath interference mechanism Core innovation: The Time Reversal Mirror (TRM) algorithm is used to perform time reversal and phase conjugation operations on the received signal, so that the multipath energy is focused on the main path.

[0011] 3. Passive wideband receiver design Core innovation: The receiver achieves impedance transformation through a piezoelectric ceramic sheet (PZT-5A) + LC parallel network.

[0012] 4. Channel Adaptive Modulation Strategy Core innovation: The subcarrier center frequency is dynamically configured based on the metal transmission spectrum, combined with pre-equalization of the transmit power.

[0013] In summary, this invention achieves high-speed, low-error-rate data penetration communication without compromising the integrity of the metal barrier by employing key technologies such as resonant excitation, multi-frequency modulation, collaborative design of piezoelectric transducers and LC impedance matching networks, and time-reversal mirror (TRM) algorithm to suppress multipath interference. Attached Figure Description

[0014] Figure 1 This is a simplified schematic diagram of the system structure of the present invention; Figure 2 This is a schematic diagram of the overall system of the present invention; Figure 3 This is a schematic diagram of the acoustic signal transmitting circuit of the present invention; Figure 4 This is a schematic diagram of the acoustic signal receiving circuit of the present invention. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0016] Before formally describing the present invention, a general description of the solution of the present invention will be given first to facilitate understanding.

[0017] Please refer to Figures 1-2 , Figure 1 This is a simplified schematic diagram of the system structure of the present invention. Figure 2 This is a schematic diagram of the overall system of the present invention; This invention provides an active device internal acoustic wave penetration communication system, comprising: Sound signal transmitting circuit, metal barrier and sound signal receiving circuit; The acoustic signal transmitting circuit is deployed on one side of the metal barrier to actively generate acoustic signals and excite the metal structure in the metal barrier to generate resonant signals. An acoustic signal receiving circuit is deployed on the other side of the metal barrier to receive the resonant signal and demodulate it to obtain the communication digital information in the acoustic emission signal; Butyl rubber is used as the contact medium between the acoustic signal transmitting circuit and the metal, and also as the contact medium between the acoustic signal receiving circuit and the metal.

[0018] Please refer to Figure 3 , Figure 3 This is a schematic diagram of an acoustic signal transmitting circuit. It should be noted that the acoustic signal transmitting circuit includes: a digital signal source, a modulator, a power amplifier, and a piezoelectric transmitter. The digital signal source is electrically connected to the modulator; the modulator is electrically connected to the power amplifier; the power amplifier is electrically connected to the piezoelectric transmitter through a first LC parallel network.

[0019] A digital signal source provides the raw data bitstream; a modulator maps the raw data bitstream onto multiple subcarriers to form a modulated signal; a power amplifier amplifies the modulated signal to drive the piezoelectric transmitter; a first LC parallel network adjusts the operating frequency of the digital signal source; the piezoelectric transmitter generates acoustic excitation during operation, and the metal plate of the metal barrier, when subjected to this acoustic excitation, will resonate at its natural resonant frequency. It generates a significant energy transmission window in and near the frequency band, forming a resonant signal.

[0020] The modulator adopts an orthogonal frequency division multiplexing (OFDM) architecture, setting 12 subcarriers at frequencies with high transmittance.

[0021] As one embodiment, the driving signal source in this invention consists of a digital signal source, a modulator, and a power amplifier.

[0022] The digital signal source provides the raw data bit stream (such as battery status, sensor data, etc.); the modulator maps the data onto multiple subcarriers to form an OFDM / NOM signal; and the power amplifier amplifies the signal amplitude to drive the piezoelectric transducer (i.e., the piezoelectric receiver).

[0023] The output characteristics of the driving signal source are as follows: Output frequency range: 24–35kHz (covering the primary and secondary resonant frequency bands); Output voltage amplitude: Adjustable, maximum peak-to-peak value approximately 100Vpp; Output impedance: 50Ω matching; Modulation method: OFDM, supporting 12 subcarriers; Amplifier type: Class A / Class B hybrid power amplifier; Control interfaces: SPI / I²C / UART, facilitating integrated control; Please refer to Figure 2 , Figure 2 This is a schematic diagram of an acoustic signal transmitting circuit.

[0024] The driving signal source consists of a digital signal source, a modulator, and a power amplifier. The output of the power amplifier is connected to an LC parallel resonant network to achieve efficient energy transfer with the piezoelectric transducer.

[0025] The operating frequency of the driving signal source must match the resonant frequency of the LC parallel network, where the inductor L is approximately 2.15mH and the capacitor C is approximately 15nF; the resonant frequency is: =28.0kHz.

[0026] Furthermore, this invention employs an orthogonal frequency division multiplexing (OFDM) architecture and positions the 12 subcarriers at frequencies with high transmittance. The center frequencies and corresponding transmittances of each subcarrier are shown in the table below: Table 1 Center frequency and corresponding transmittance of each subcarrier

[0027] This distribution strategy ensures that each subcarrier is in a high-transmission region, thereby improving the overall signal-to-noise ratio and communication reliability.

[0028] The transmitter uses Orthogonal Frequency Division Multiplexing (OFDM) modulation to map raw data (such as battery status and sensor readings) onto multiple subcarriers. The modulation symbol for each subcarrier is denoted as... ( =0,1,…, -1, where (Total number of subcarriers).

[0029] The receiver obtains the TRM algorithm and frequency domain demodulation. That is to The restoration.

[0030] Transmit signal It can be represented as:

[0031] The receiver extracts the data using the TRM algorithm. and The relationship is:

[0032] in It is the frequency domain component of the inverted signal. It is the channel frequency response. By compensating for channel effects, After data processing (TRM), the original symbols are processed. The restoration.

[0033] In summary, the digital source provides the raw data bitstream; the modulator maps the raw data bitstream onto multiple subcarriers to form a modulated signal; the power amplifier amplifies the modulated signal to drive the piezoelectric transmitter; the first LC parallel network adjusts the operating frequency of the digital source; and the piezoelectric transmitter generates acoustic excitation during operation. When the metal plate of the metal barrier is subjected to this acoustic excitation, it will resonate at its natural resonant frequency. It generates a significant energy transmission window in and near the frequency band, forming a resonant signal.

[0034] The following section describes the basic physical mechanism by which sound waves penetrate metal barriers.

[0035] When a metal plate is excited by acoustic waves from the aforementioned piezoelectric transducer (piezoelectric receiver), it will resonate at its natural resonant frequency. It generates a significant energy transmission window in and adjacent frequency bands.

[0036] This phenomenon is determined by the resonant coupling effect, and its acoustic intensity transmittance can be expressed as: (1) in: : Describes the ability of a sound wave at a certain frequency to penetrate a metal structure; it is the frequency. The sound intensity transmission coefficient at a given point, a dimensionless parameter, has a value range of 0 ≤ ≤1, the closer the value is to 1, the higher the sound wave penetration efficiency at that frequency.

[0037] The quality factor of the system (dimensionless). : Principal resonant frequency; Imaginary unit ( =−1) Without optimization, the quality factor of low-carbon steel plate is approximately =15, taking a 2mm thick low-carbon steel plate as an example, the measured principal resonant frequency is... =28.0kHz, the corresponding 3dB bandwidth is:

[0038] 3dB bandwidth is the bandwidth from the center frequency in the system frequency response curve. Initially, transmittance (or other performance indicators) decreases to its peak value. (That is, the frequency range corresponding to approximately -3dB.)

[0039] Although a single resonant peak provides only a limited bandwidth, the system quality factor can be significantly reduced by introducing an acoustic coupling layer (such as butyl rubber) and an electrical impedance matching network. ≈2.3, thus extending the effective bandwidth to:

[0040] in: : It is reduced by the damping layer The quality factor after value adjustment.

[0041] Effective bandwidth refers to the actual usable communication bandwidth of a system, which is usually determined by several factors, including the primary resonant frequency, the secondary resonant frequency, and the quality factor of the damping layer and impedance matching network. The adjustment effect. The effective bandwidth comprehensively considers the resonant characteristics of the metal casing and the frequency response capability of the transducer, and is the frequency range that the system actually supports for communication.

[0042]

[0043] in, : Electromechanical coupling coefficient of piezoelectric ceramics.

[0044] In addition, two secondary resonance peaks exist at frequencies of 26.0 kHz and 30.5 kHz, which further broaden the range of the high transmission plateau region, forming a continuous effective communication frequency band from 26.0 to 30.5 kHz.

[0045] Next, the acoustic signal receiving circuit section of this application will be described. Please refer to... Figure 3 , Figure 3 This is a schematic diagram of an acoustic signal receiving circuit.

[0046] Please refer to Figure 4 , Figure 4 This is a schematic diagram of an acoustic signal receiving circuit; the acoustic signal receiving circuit includes: a second LC parallel network, a piezoelectric receiver, a preamplifier, an ADC sampling module, and a TRM processor; one side of the LC parallel network is grounded, and the other side is electrically connected to the piezoelectric receiver; the piezoelectric receiver is electrically connected to the preamplifier; the preamplifier is electrically connected to the ADC sampling module; the ADC sampling module is electrically connected to the TRM processor.

[0047] The second LC parallel network is used to match the impedance of the preceding and following stages, improving the signal-to-noise ratio. The piezoelectric receiver utilizes the positive piezoelectric effect of the piezoelectric material to convert the received resonant signal into an analog electrical signal output. The preamplifier receives the analog electrical signal output from the piezoelectric receiver, amplifies it, and then sends it to the ADC sampling module for digitization to obtain a digital signal. The digital signal is processed by the TRM processor using the Time Reversal Mirror (TRM) algorithm to obtain the reverse mirror signal. The reverse mirror signal is demodulated and restored to obtain the original data bitstream.

[0048] It should be noted that when the transmitter drives the metal structure to resonate, some of the sound wave energy will penetrate the metal barrier and form a weak but detectable mechanical vibration on the other side.

[0049] The piezoelectric receiver is attached to the inside of the metal structure. Its core function is to sense the sound wave vibrations that pass through the metal barrier and convert them into electrical signals for output.

[0050] The piezoelectric receiver is preferably a device with the same PZT-5A piezoelectric ceramic sheet as the acoustic signal transmitter; that is, it is isomorphic to the transmitter and has the same frequency response characteristics; the equivalent load resistance Rsense is matched with the LC parallel network.

[0051] Piezoelectric receivers utilize the positive piezoelectric effect of piezoelectric materials to convert received mechanical vibrations into electrical signals for output.

[0052]

[0053] in: Output voltage; : Piezoelectric strain constant (typical value for PZT-5A is 250–300 pC / N); Mechanical force applied to the piezoelectric element (caused by sound wave vibration).

[0054] The electrical signal contains multiple subcarrier frequency components, reflecting the information content of the original transmitted signal.

[0055] The function of the second LC parallel network is as follows: In addition, to improve receiver sensitivity and frequency response consistency, the piezoelectric receiver is connected to a second LC parallel (resonant) network, which has the following functions: At the main resonance frequency Matching is achieved at 28.0kHz through impedance transformation; matching the impedances of the preceding and following stages improves the signal-to-noise ratio; and the receiving bandwidth is broadened to over 12kHz.

[0056] The analog signals output by the receiving sensor are usually very weak and need to be adjusted by a preamplifier before being sent to an ADC for digital processing.

[0057] 1. Amplifier Function: Amplify weak signals and improve the signal-to-noise ratio; Features: High input impedance; Programmable gain control (PGA); Differential input interference suppression; Supports 26–30kHz frequency band.

[0058] 2. ADC sampling module Function: Converts amplified analog signals into digital signals; Parameter requirements: Sampling rate ≥ 100MSPS; resolution ≥ 12bit; input bandwidth covers the effective communication frequency band (26–30kHz); output interface supports high-speed transmission protocols such as SPI and LVDS.

[0059] An active device internal acoustic wave penetration communication method, applied to an active device internal acoustic wave penetration communication system, the method includes the following steps: S1. The digital source transmits the raw data bit stream, while the modulator uses the transmitter power pre-equalization control method to control the power distribution of the power amplifier in the acoustic signal transmission circuit. It should be noted that this invention employs a pre-equalization control method for power distribution, as detailed below: Transmit power pre-equalization: According to the formula Adjust the power of each subcarrier to compensate for frequency-selective fading.

[0060] in: : Transmitted signal power spectral density, W / Hz, power distribution at frequency f at the transmitter, which is the final output transmitted signal spectrum used to drive the piezoelectric transducer.

[0061] The reference power level of the transmitted signal, in W / Hz, is a constant representing the unweighted transmitted power, typically set as the average of the system's maximum permissible power. If the total transmitted power of the system is... =100mW, and the number of subcarriers is =12, then ,in For a single subcarrier bandwidth.

[0062] The frequency response of a piezoelectric transducer is a transfer function; the piezoelectric element's frequency response is... The electromechanical-electric conversion efficiency at a given point is usually a complex number, but here we take the modulus value (amplitude-frequency response). If the piezoelectric element's response decreases at high frequencies (e.g., ...), =0.7), the power at this frequency point needs to be increased through pre-equalization.

[0063] This formula is used for transmitter power pre-equalization control, and the specific process is as follows: Frequency Scanning and Modeling: Measuring the Transmittance Curves of Metal Structures ; Measuring the frequency response of a piezoelectric transducer .

[0064] Subcarrier power calculation: For each subcarrier frequency Calculate its transmission power .

[0065] Power allocation is achieved by setting an independent gain coefficient for each subcarrier in the modulator and adjusting the power through digital pre-emphasis or a power amplifier.

[0066] S2. The power amplifier amplifies the modulation signal according to the power distribution, drives the piezoelectric transmitter to generate acoustic wave excitation, causing the metal plate to resonate and form a resonant signal. S3. The resonance signal is processed by the TRM processor of the acoustic signal receiving circuit using the TRM algorithm and then demodulated to obtain the original data bit stream.

[0067] Specifically, this invention uses the TRM algorithm for processing.

[0068] The Time Reversal Mirror (TRM) algorithm is a signal processing technique based on the time-domain symmetry of sound wave propagation. It is widely used for signal focusing and interference suppression in multipath environments. Its core idea is that by recording the time sequence of the received signal and playing it in reverse, the location of the original sound source can be accurately reconstructed or focused.

[0069] In this invention, the TRM algorithm is used to suppress complex multipath reflections inside the metal barrier, significantly improving the signal-to-noise ratio (SNR) at the receiver, thereby reducing the communication bit error rate.

[0070] The mathematical model of the TRM algorithm is as follows: 1. Received signal model and multipath interference analysis Multipath model of received signal: Let the transmitted signal be Receive signal It is composed of the superposition of reflected signals from multiple paths, and can be represented as:

[0071] in: :Number of multipaths; : No. Complex gain of each path (including amplitude attenuation and phase shift); : No. The delay of the path; Transmitted signal (such as OFDM symbol).

[0072] Physical meaning: The signal in each path is delayed due to time delay. and attenuation The difference is that it causes time-domain spread and frequency-domain distortion at the receiving end; Multipath interference can lead to a decrease in inter-carrier crosstalk (ICI) and signal-to-noise ratio (SNR).

[0073] 2. Mathematical Modeling of the TRM Algorithm A. Time reversal operation: For the received signal Perform a time reversal operation to generate a reversal signal. :

[0074] Physical meaning: Time reversal is equivalent to reducing the time delay of each path. Flip to - ; Simultaneously, complex gain Take conjugate This compensates for the phase shift; during subsequent propagation, the energy from all paths will reconverge at the original launch point.

[0075] B. Multipath Energy Focusing: By performing a time reversal operation, the signal energy of all paths is compressed in the time domain to the vicinity of the main path, forming a sharp main peak. The mathematical expression is as follows: Reversed signal The time-domain waveform is as follows:

[0076] When the signal travels through the original propagation path again (i.e., the "secondary propagation" process of the TRM algorithm), the time delay of each path is canceled out, and the signal energy is refocused on the main path:

[0077] in This represents the channel impulse response. The final result is:

[0078] Conclusion: The main path signal s(t) is enhanced; multipath interference is suppressed, and the signal-to-noise ratio is significantly improved.

[0079] C. Frequency Domain Demodulation and Channel Compensation Reverse signal After the signal is input to the receiving end signal processor, the following steps are performed: First, Fourier transform is used to extract frequency domain information: Performing a Fast Fourier Transform (FFT) on the inverted signal yields the frequency domain signal:

[0080] in: : No. The frequency of each subcarrier; : Reversal signal at The frequency domain components at that location.

[0081] In This refers to the Fourier Transform, which transforms the received signal after time reversal. The process involves converting from the time domain to the frequency domain to facilitate subsequent subcarrier demodulation and channel compensation.

[0082] Secondly, channel response measurement: Channel response is measured using training sequences or pilot signals. :

[0083] Symbolic demodulation: Based on the frequency of each subcarrier The channel response at the location demodulates the received symbols:

[0084] in: : No. Equivalent channel response at each subcarrier (adaptively corrected by TRM). : The symbol estimate after demodulation.

[0085] The TRM algorithm uses a time reversal operation to cause the energy of multipath signals to overlap in the time domain, forming a main peak; during frequency domain demodulation, the channel response... It is equalized, eliminating the need for complex channel estimation modules.

[0086]

[0087] Modulation symbols directly associated with the transmitter This is the core intermediate quantity for signal reconstruction. Through... Reconstructable The frequency domain characteristics, but in practical systems, they are usually directly applied to... Decoding can be performed without explicitly reconstructing the time-domain signal.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An active device internal acoustic wave penetration communication method, applied to an active device internal acoustic wave penetration communication system, the system comprising an acoustic signal transmitting circuit, a metal barrier and an acoustic signal receiving circuit; The acoustic signal transmitting circuit is deployed on one side of the metal barrier to actively generate acoustic signals and excite the metal structure in the metal barrier to generate resonant signals. The acoustic signal receiving circuit is deployed on the other side of the metal barrier to receive the resonant signal and demodulate it to obtain the communication digital information in the acoustic emission signal; Butyl rubber is used as the contact medium between the acoustic signal transmitting circuit and the metal, and also as the contact medium between the acoustic signal receiving circuit and the metal. The acoustic signal transmitting circuit includes: Digital signal source, modulator, power amplifier, and piezoelectric transmitter; The digital signal source is electrically connected to the modulator; The modulator is electrically connected to the power amplifier; the power amplifier is electrically connected to the piezoelectric transmitter through the first LC parallel network. Digital sources are used to provide raw data bitstreams; The modulator maps the original data bitstream onto multiple subcarriers to form a modulated signal; the power amplifier amplifies the modulated signal to drive the piezoelectric transmitter; the first LC parallel network adjusts the operating frequency of the digital source; when the piezoelectric transmitter operates, it generates acoustic excitation, and the metal plate of the metal barrier, when subjected to the aforementioned acoustic excitation, will resonate at its natural resonant frequency. It generates a significant energy transmission window in and its adjacent frequency bands, forming a resonant signal; The acoustic signal receiving circuit includes: a second LC parallel network, a piezoelectric receiver, a preamplifier, an ADC sampling module, and a TRM processor; one side of the LC parallel network is grounded, and the other side is electrically connected to the piezoelectric receiver; the piezoelectric receiver is electrically connected to the preamplifier; the preamplifier is electrically connected to the ADC sampling module; and the ADC sampling module is electrically connected to the TRM processor. The second LC parallel network is used to match the impedance of the preceding and following stages of the circuit, improving the signal-to-noise ratio; the piezoelectric receiver utilizes the positive piezoelectric effect of the piezoelectric material to convert the received resonant signal into an analog electrical signal output; the preamplifier receives the analog electrical signal output from the piezoelectric receiver, amplifies it, and then sends it to the ADC sampling module for digitization processing to obtain a digital signal; the digital signal is processed by the TRM processor using the Time Reversal Mirror (TRM) algorithm to obtain the reverse mirror signal; the reverse mirror signal is demodulated and restored to obtain the original data bitstream. The method is characterized by the following steps: S1. The digital source transmits the raw data bit stream, while the modulator uses the transmitter power pre-equalization control method to control the power distribution of the power amplifier in the acoustic signal transmission circuit. S2. The power amplifier amplifies the modulation signal according to the power distribution, drives the piezoelectric transmitter to generate acoustic wave excitation, causing the metal plate to resonate and form a resonant signal. S3. The resonance signal is processed by the TRM processor of the acoustic signal receiving circuit using the TRM algorithm and then demodulated to obtain the original data bit stream. The specific method for transmitter power pre-equalization control is as follows: S11. Measure the transmittance curve of the metal barrier structure. ; S12. Measure the frequency response of the piezoelectric receiver. ; S13, For each subcarrier frequency of the modulator Calculate its transmission power : in, Indicates the reference power level of the transmitted signal; S14. Set an independent gain coefficient for each subcarrier in the modulator; adjust the power through digital pre-equalization or power amplifier.

2. The active device internal acoustic wave penetration communication method as described in claim 1, characterized in that: The processing procedure of the TMR algorithm in step S3 is as follows: S31. Regarding the received resonance signal r (t) Perform time inversion operation to generate inverted signal. ; S32. Perform a Fast Fourier Transform on the inverted signal to obtain the frequency domain signal. ; S33. Measure the channel response using training sequences or pilot signals. ; S34. Demodulate the signal based on the frequency domain signal and channel response to obtain the demodulated signal: ; S35. Restore the original transmitted signal based on the demodulated signal. s ( t ), which is the raw data bit stream.

3. The active device internal acoustic wave penetration communication method as described in claim 2, characterized in that: The specific process of generating the inverted signal in step S31 is as follows: S311, Receiving Signal It is composed of the superposition of reflected signals from multiple paths, and is represented as: in, Indicates the number of multipaths; Indicates the first Complex gain of the path; Indicates the first The delay of the path; Indicates the original transmitted signal; S312, Regarding the received signal Perform a time reversal operation to generate a reversal signal. : By performing a time reversal operation, the signal energy of all paths is compressed in the time domain to the vicinity of the main path, forming a sharp main peak; S313. When the signal passes through the original propagation path again, i.e., the secondary propagation process of the TRM algorithm, the time delay of each path... τ i The signal is canceled out, and the signal energy is refocused on the main path. in For channel impulse response, This represents a convolution operation, and the final result is: Indicates the original transmission signal of the main path s ( t The signal is enhanced, and multipath interference is suppressed.

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