Cross-medium cooperative sensing and communication method applied to wave glider platform

Abstract

The application provides a cross-medium cooperative sensing underwater acoustic communication method applied to a wave glider platform, comprising the following steps: acquiring a wave height parameter by using a wave height instrument carried on the wave glider platform, and performing cross-medium cooperative estimation on sea surface dynamic parameters based on a correlation between the wave height parameter and dynamic characteristics of sea surface waves; for a slowly-varying underwater acoustic channel, setting a channel update time of a time reversal underwater acoustic communication receiver by using a stationary time corresponding to the wave height parameter, periodically acquiring underwater acoustic channel characteristics to ensure that the parameters of the time reversal receiver are adapted to the channel; and for a fast-varying underwater acoustic channel, using time reversal channel estimation to reduce the number of periodic channel estimation times. The method fully utilizes the characteristics that the wave glider platform works at the water-air interface, and provides a kind of underwater acoustic communication method which is adapted to the working characteristics of the wave glider platform.

Description

Technical Field

[0001] This invention relates to the field of underwater acoustic communication technology, and in particular to a cross-medium collaborative sensing underwater acoustic communication method applied to a wave glider platform. Background Technology

[0002] As a new type of unmanned system platform operating at the water-air interface, wave gliders have outstanding advantages such as crossing the water-air interface, long-term operation, convenient deployment and recovery, and unmanned operation. In recent years, they have been widely studied and applied in the fields of underwater information transmission, detection, positioning, and monitoring.

[0003] For underwater acoustic communication systems on wave glider platforms, the sound propagation process is greatly affected by the sea surface because the transducers of the underwater acoustic communication system are lowered to a shallower depth. Dynamic sea surface reflection under uncertain marine hydrological and meteorological conditions such as wind, waves, tides, and swells is the main cause of time-varying underwater acoustic channels and is also the main factor affecting the underwater acoustic communication performance of such vehicles.

[0004] Currently, there is no dedicated underwater acoustic communication method or equipment for wave gliders. They are usually provided with underwater communication capabilities by directly mounting existing underwater acoustic communication equipment. Therefore, the special characteristics of wave gliders as a new type of unmanned system platform that operates at the water-air interface are not fully considered.

[0005] Time reversal technology, through time-reversal focusing, effectively suppresses multipath propagation and has become a hot research topic in underwater acoustic communication in recent years. The prerequisite for ensuring time reversal performance is that the channel remains relatively stable within the processing time window. However, actual underwater acoustic channels often exhibit complex and random time-varying characteristics. To guarantee the performance of time-reversal communication receivers under time-varying conditions, the replica channel response is typically designed to be updated periodically to handle time variations. To eliminate residual inter-symbol interference, a single-channel decision feedback equalizer is usually used after the time-reversal processor to form a classic time-reversal receiver structure. The time-reversal processor then updates periodically using a traditional estimation algorithm to handle time variations.

[0006] In some existing technologies, time-reflection processors (RTPs) are adapted to time-varying environments by periodically performing least-squares estimation to update the channel impulse response block by block. However, in complex marine environments, underwater acoustic channels are affected by a combination of non-stationary phenomena with different mechanisms and time-varying scales. Therefore, the update period of such periodically updated RTPs is difficult to optimize and determine in real-time for practical underwater acoustic communication applications. In particular, an inappropriate update period in rapidly varying underwater acoustic channels leads to a sharp decline in RTP performance, severely impacting underwater acoustic communication performance; while in slowly varying underwater acoustic channels, an excessively small update period increases the system overhead for channel estimation, resulting in decreased communication efficiency.

[0007] Existing technologies have also proposed a time-reversal receiver architecture that uses Kalman filtering to track the time-reversal channel, combining a time-reversal processor driven by a Kalman filter estimator with a single-channel decision feedback equalizer. However, the assumption that Kalman filtering is based on a linear time-varying model cannot guarantee compliance with the dynamic time-varying characteristics of the underwater acoustic channel. Furthermore, using Kalman filtering in slowly varying underwater acoustic channels can introduce unnecessary system complexity overhead.

[0008] In fact, unlike traditional underwater vehicles such as AUVs, ROVs, and manned submersibles, which are carried by underwater acoustic communication systems, unmanned vehicles such as wave gliders, which operate at the water-air interface, have the conditions to measure marine hydrological and meteorological phenomena. Therefore, they can obtain dynamic sea surface characteristic parameters (such as wave height) that cause time-varying underwater acoustic channels from the perspective of cross-media collaborative sensing, and provide prior information for time-reversed underwater acoustic communication receivers to optimize underwater acoustic communication reception and processing. Traditional underwater acoustic communication systems have not considered this feature in their design and engineering applications. Summary of the Invention

[0009] To address the technical problem that traditional underwater acoustic communication systems do not consider acquiring dynamic sea surface characteristic parameters (such as wave height) that cause time-varying underwater acoustic channels from the perspective of cross-medium collaborative sensing, and to provide prior information for optimizing underwater acoustic communication reception and processing for time-reversed underwater acoustic communication receivers, this invention proposes a cross-medium collaborative sensing underwater acoustic communication method applied to wave glider platforms.

[0010] This invention proposes a cross-medium cooperative sensing underwater acoustic communication method for wave glider platforms, the method comprising:

[0011] Wave height parameters are obtained using a wave height meter mounted on a wave glider platform, and cross-media collaborative estimation of sea surface dynamic parameters is performed based on the correlation between wave height parameters and sea surface wave dynamic characteristics.

[0012] For slowly varying underwater acoustic channels, the channel update time of the time-reversal underwater acoustic communication receiver is set using the stationary time corresponding to the wave height parameter, and the underwater acoustic channel characteristics are periodically acquired to ensure the adaptation of the time-reversal receiver parameters to the channel.

[0013] For rapidly changing underwater acoustic channels, time-inverse channel estimation is used to reduce the number of times the channel estimation is periodically updated.

[0014] In some specific embodiments, the wave height meter acquires the wave height parameter H to estimate the wave period T. Set threshold T TH Based on whether the wave period T is less than or greater than T TH Determine whether the underwater acoustic channel is slowly or rapidly changing, and perform corresponding underwater acoustic communication reception processing.

[0015] In some specific embodiments, the slow-varying underwater acoustic channel specifically includes:

[0016] Assume the impulse response of the i-th channel is h i (t), the information symbol received by the i-th channel is s. ir (t), Where, n is (t) represents the interference noise superimposed on the information signal. This represents the convolution operation;

[0017] At the receiver, the underwater acoustic channel response h′ is obtained by periodically updating the channel estimate according to the wave period T. i (t), and h′ obtained by time reversal of it. i (-t) is used as the time-reflection preprocessor p ir The coefficients of (t), the received symbol information s ir (t) after the time-reversal preprocessor p ir (t), that is, with h′ i (-t) convolution operation Where, n i (t) represents the noise interference term; For time-inverse channeling, n i (t) represents the noise interference term of the i-th channel. After each channel passes through its respective time-reflection preprocessor, the signal is r. i Given n′(t) and s′(t) after multi-channel merging, the noise interference term is n′(t), and the signal is s′(t). Then, the expressions for the inverted signal and noise interference term in the M-channel case are as follows: Where M is the number of receiving channels in the underwater acoustic communication system; the time-reverse channel through which the signal s(t) passes is the convolution of the autocorrelation of the channel impulse response and the autocorrelation of the probe signal:

[0018] In some specific embodiments, a single-channel decision feedback equalizer is cascaded after time reversal processing to suppress residual multipath.

[0019] In some specific embodiments, for a fast-changing underwater acoustic channel, time-inverse channel estimation is embedded in a time-inverting receiver to obtain an estimate q′(t) of the time-inverse channel q(t). This is in response to the time-inverse channel estimation error Error exceeding a preset threshold E. TH Channel estimation is performed to update the channel response of the time-inverting processor.

[0020] In some specific embodiments, the time-reversal channel estimation error is calculated by comparing the time-reversal channel q(t) estimate with the underwater acoustic channel estimates h for each channel. i The absolute value of the error (t) is obtained by summing over the channel response length L:

[0021] This invention proposes a cross-medium cooperative sensing underwater acoustic communication system for wave glider platforms, characterized in that the system comprises:

[0022] Wave glider platform: The wave glider platform is equipped with a wave height meter to obtain wave height parameters, and performs cross-media collaborative estimation of sea surface dynamic parameters based on the correlation between wave height parameters and sea surface wave dynamic characteristics;

[0023] Underwater acoustic channel processing unit: configured to, for slowly varying underwater acoustic channels, use the stationary time corresponding to the wave height parameter to set the channel update time of the time-reversed underwater acoustic communication receiver, and periodically acquire underwater acoustic channel characteristics to ensure the adaptation of the time-reversed receiver parameters to the channel; for rapidly varying underwater acoustic channels, time-reversed channel estimation is used to reduce the number of periodic channel estimation updates.

[0024] In some specific embodiments, the wave height meter acquires the wave height parameter H to estimate the wave period T. Set threshold T TH Based on whether the wave period T is less than or greater than T TH Determine whether the underwater acoustic channel is slowly or rapidly changing, and perform corresponding underwater acoustic communication reception processing.

[0025] In some specific embodiments, the slow-varying underwater acoustic channel specifically includes:

[0026] Assume the impulse response of the i-th channel is h i (t), the information symbol received by the i-th channel is s. ir (t), Where, n is (t) represents the interference noise superimposed on the information signal. This represents the convolution operation;

[0027] At the receiver, the underwater acoustic channel response h′ is obtained by periodically updating the channel estimate according to the wave period T. i (t), and h′ obtained by time reversal of it. i (-t) is used as the time-reflection preprocessor p ir The coefficients of (t), the received symbol information s ir (t) after the time-reversal preprocessor p ir (t), that is, with h′ i (-t) convolution operation Where, n i (t) represents the noise interference term; For time-inverse channeling, n i (t) represents the noise interference term of the i-th channel. After each channel passes through its respective time-reflection preprocessor, the signal is r. i Given n′(t) and s′(t) after multi-channel merging, the noise interference term is n′(t), and the signal is s′(t). Then, the expressions for the inverted signal and noise interference term in the M-channel case are as follows: Where M is the number of receiving channels in the underwater acoustic communication system; the time-reverse channel through which the signal s(t) passes is the convolution of the autocorrelation of the channel impulse response and the autocorrelation of the probe signal: After time reversal processing, a single-channel decision feedback equalizer is cascaded to suppress residual multipath.

[0028] In some specific embodiments, for a fast-changing underwater acoustic channel, time-inverse channel estimation is embedded in a time-inverting receiver to obtain an estimate q′(t) of the time-inverse channel q(t). This is in response to the time-inverse channel estimation error Error exceeding a preset threshold E. TH Channel estimation is performed to update the channel response of the time-reversal processor. The time-reversal channel estimation error is calculated by comparing the time-reversal channel q(t) estimation with the underwater acoustic channel estimation h for each channel. i The absolute value of the error (t) is obtained by summing over the channel response length L:

[0029] This invention addresses the rapidly developing unmanned vehicle platform of wave gliders, disclosing a cross-medium collaborative sensing optimization method for underwater acoustic communication. This method utilizes dynamic sea surface characteristic parameters, such as wave height, acquired across media by a wave height meter on the surface portion of the wave glider platform operating at the water-air interface. It then performs collaborative sensing optimization of the underwater acoustic communication system mounted on the underwater portion of the wave glider, specifically adapting and specifically processing the time-varying parameters of the underwater acoustic channel. This provides a new type of underwater acoustic communication method adapted to the platform's operational characteristics for wave gliders. Attached Figure Description

[0030] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain the principles of the invention. Other embodiments and many anticipated advantages of the embodiments will be readily recognized as they become better understood through reference to the following detailed description. Other features, objects, and advantages of this application will become more apparent from reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0031] Figure 1 This is a flowchart of a cross-medium collaborative sensing optimization underwater acoustic communication method applied to a wave glider platform, according to an embodiment of this application.

[0032] Figure 2This is a schematic diagram of cross-media collaborative sensing and optimization of underwater acoustic communication for a wave glider, according to a specific embodiment of this application.

[0033] Figure 3 This is a flowchart of cross-media cooperative sensing fast-change and slow-change channel determination, which is a specific embodiment of this application.

[0034] Figure 4 This is a flowchart of the collaborative sensing optimization underwater acoustic communication receiver, which is a specific embodiment of this application.

[0035] Figure 5 This is a framework diagram of a cross-media collaborative sensing and optimization underwater acoustic communication system applied to a wave glider platform, according to one embodiment of this application. Detailed Implementation

[0036] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0037] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] A cross-medium collaborative sensing optimization underwater acoustic communication method for a wave glider platform, according to one embodiment of this application. Figure 1 A flowchart illustrating a cross-medium collaborative sensing underwater acoustic communication method applied to a wave glider platform according to an embodiment of this application is shown. Figure 1 As shown, the method includes the following steps:

[0039] S100: Wave height parameters are obtained using a wave height meter mounted on a wave glider platform, and cross-media collaborative estimation of sea surface dynamic parameters is performed based on the correlation between wave height parameters and sea surface wave dynamic characteristics.

[0040] In a specific embodiment, Figure 2 A schematic diagram of cross-medium cooperative sensing optimization underwater acoustic communication for a wave glider, according to a specific embodiment of this application, is shown. Figure 2 As shown, after the wave glider platform obtains wave height parameters using a wave height meter commonly used in the field on the water surface part of the platform, it can perform cross-media collaborative estimation of sea surface dynamic parameters based on the correlation between wave height and sea surface wave dynamic characteristics. Furthermore, it can classify and distinguish slow-changing and fast-changing underwater acoustic channels by setting thresholds.

[0041] In specific embodiments, traditional time-reversal underwater acoustic communication receivers under time-varying underwater acoustic channel conditions need to combine periodic channel estimation updates to ensure processing performance. For time-varying underwater acoustic channels under uncertain marine environmental conditions, it is difficult to guarantee a suitable value for the period T. An inappropriate period T often leads to a sharp decline in time-reversal performance or a significant reduction in communication efficiency. Considering that typical water-air interface platforms such as wave gliders have the ability to acquire marine dynamic characteristics, the cross-medium cooperative sensing optimization underwater acoustic communication method disclosed in this application directly uses the wave height parameters obtained by the wave height meter equipped on the wave glider platform to evaluate the time-varying degree of the underwater acoustic channel in a cross-medium cooperative sensing manner, thereby classifying the underwater acoustic channel as fast-changing or slow-changing according to a set threshold.

[0042] In a specific embodiment, Figure 3 A flowchart illustrating a specific embodiment of this application for cross-media cooperative sensing fast-changing and slow-changing channel determination is shown, as follows: Figure 3 As shown, wave boat platforms, a typical water-air interface carrier, can obtain wave height parameter H through cross-medium collaborative sensing, and then use the formula... The channel time-varying period T parameter is estimated using the formula, and further, a threshold T is set. TH It can be based on whether the T value is less than or greater than T. TH Slow-changing and fast-changing underwater acoustic channels are determined, and corresponding underwater acoustic communication reception processing is performed accordingly. If T < T TH If T > T, then it is a slowly varying channel. TH This is a fast-changing channel.

[0043] S201: For slowly varying underwater acoustic channels, the channel update time of the time-reversing underwater acoustic communication receiver is set using the stationary time corresponding to the wave height parameter. The underwater acoustic channel characteristics are periodically acquired to ensure the adaptation of the time-reversing receiver parameters to the channel and to maximize the available communication efficiency.

[0044] In specific embodiments, considering the inter-symbol interference caused by severe multipath effects in marine acoustic channels, time-reversal calculation can effectively suppress multipath and utilize multipath energy to improve communication performance by estimating channel characteristics and performing space-time reversal focusing. For a multi-channel underwater acoustic communication system, assume the impulse response of the i-th channel is h. i (t) satisfies randomness. This represents the convolution operation. Let s be the information symbol received by the i-th channel. ir (t), Where, n is (t) represents the interference noise superimposed on the information signal.

[0045] At the receiver, the underwater acoustic channel response h′ is obtained by periodically updating the channel estimate according to period T. i(t), and h′ obtained by time reversal of it. i (-t) is used as the time-reflection preprocessor p ir The coefficient of (t) is the received symbol information s. ir (t) after the time-reversal preprocessor p ir (t), that is, with h′ i (-t) convolution operation Where, n i (t) represents the noise interference term; This is called the time-reflection channel, which can be approximated as δ(t) under ideal waveguide conditions. i (t) represents the noise interference term of the i-th channel.

[0046] After each channel passes through its respective time-reflection preprocessor, the signal is r. i (t); the noise interference term is n. i Given n′(t) and s′(t) after multi-channel merging, the noise interference term is n′(t); the signal is s′(t). Then, the expressions for the inverted signal and noise interference term in the M-channel case are as follows: Where M is the number of receiving channels in the underwater acoustic communication system, and the time-reverse channel through which the signal s(t) passes is actually the convolution of the autocorrelation of the channel impulse response and the autocorrelation of the probe signal: When the acoustic channel is complex and the autocorrelation peak of the probe signal is sharp, the channel can be approximated as a time-reflection channel. In the ideal case where the noise interference term is approximated as white noise, s′(t) can be approximated as the signal s(t) at the time of transmission. That is, after the multi-channel signals are combined through their respective time-reflectors, the signals are not only focused to eliminate multipath and restore the original signal, but also multipath focusing is achieved in the spatial and temporal domains, thereby improving the signal processing gain.

[0047] Underwater acoustic channel estimation methods, such as least squares and orthogonal matching pursuit algorithms, are used for periodic channel estimation to obtain periodically updated channel characteristics h′. i (t) T The remaining inter-symbol interference after time reversal processing, such as... Figure 4 As shown, a single-channel decision feedback equalizer (DFE) is cascaded after time reversal processing to suppress residual multipath, thus forming a configuration as shown in the diagram for slow-varying underwater acoustic channels. Figure 4 The diagram shows the workflow of the collaborative sensing optimization underwater acoustic communication receiver.

[0048] S202: For fast-changing underwater acoustic channels, time-inverse channel estimation is used to reduce the number of periodic channel estimation updates. Considering that after time-inverse processing, the equivalent time-inverse channel response under the time-inverse processing structure exhibits a much slower time-varying nature compared to the original underwater acoustic channel response, time-inverse channel estimation can effectively reduce the number of periodic channel estimation updates and improve communication efficiency.

[0049] In a specific embodiment, for a fast-changing underwater acoustic channel, the equivalent time-reversed channel q(t) after time reversal processing will exhibit slower time changes than the original underwater acoustic channel. Therefore, compared to the fast-changing underwater acoustic channel, the time-reversed channel after time-reversal processing has slow time-varying characteristics, which is beneficial to reduce the number of channel estimation updates and improve communication efficiency. At the same time, the channel estimator based on dynamic compressed sensing can take advantage of the time-varying sparsity of the time-reversed underwater acoustic channel, which can effectively improve the performance of time-reversed underwater acoustic communication.

[0050] refer to Figure 4 The flowchart shown illustrates the collaborative sensing optimization of the underwater acoustic communication receiver. Time-inverse channel estimation is embedded into the time-inverse receiver to obtain the estimated time-inverse channel q(t), q′(t). The time-inverse channel estimation error (Error) is only applied when it exceeds a preset threshold E. TH At that time, a channel estimation method is used to estimate the channel response h′ of the time-reversal processor. i This significantly reduces the number of periodic channel updates required for rapidly changing underwater acoustic channels in traditional time-reversal receiver mode. The time-reversal channel estimation error is calculated by comparing the time-reversal channel q(t) estimate with the underwater acoustic channel estimates h′ for each channel. i The absolute value of the error (t) is obtained by summing over the channel response length L, as shown in the following equation:

[0051] In a specific embodiment, based on the channel dynamic characteristic parameters obtained through cross-media collaborative sensing optimization, in the case of a rapidly changing underwater acoustic channel, it is only necessary to ensure that the time-inverse channel estimation error Error is greater than a preset threshold E. TH Only when the channel estimation is updated (h′) is the underwater acoustic channel estimation required. i (t), which greatly reduces the system overhead of periodic estimation based on the fast-changing underwater acoustic channel period and improves communication efficiency. After determining whether to update the channel estimation through time-inverse channel estimation, the output of the time-inverse processing is also sent to a single-channel decision feedback equalizer, and finally the decoding result is output.

[0052] This invention targets wave gliders, a rapidly developing type of unmanned vehicle platform in recent years. It fully utilizes the characteristic of wave glider platforms operating at the water-air interface, employs a wave height meter mounted on the water surface of the wave glider platform to obtain wave height parameters, and estimates the dynamic characteristics of the underwater acoustic channel through cross-medium collaborative sensing. Then, it performs classification of slow-changing and fast-changing underwater acoustic channels, and conducts a collaborative optimization design suitable for wave gliders based on a multi-channel time-reversal underwater acoustic communication receiver. Thus, it provides a type of underwater acoustic communication method adapted to the platform's operating characteristics for wave gliders.

[0053] Figure 5 A framework diagram of a cross-medium cooperative sensing and optimization underwater acoustic communication system for a wave glider platform according to an embodiment of this application is shown. The system includes a cross-medium cooperative estimation unit 501 for sea surface dynamic parameters and an underwater acoustic channel processing unit 502.

[0054] In a specific embodiment, the cross-medium collaborative estimation unit 501 for sea surface dynamic parameters is equipped with a wave height meter on the wave glider platform to obtain wave height parameters. Based on the correlation between wave height parameters and sea surface wave dynamic characteristics, cross-medium collaborative estimation of sea surface dynamic parameters is performed. The underwater acoustic channel processing unit 502 is configured to, for slowly varying underwater acoustic channels, use the stationary time corresponding to the wave height parameters to set the channel update time of the time-reversed underwater acoustic communication receiver, and periodically acquire underwater acoustic channel characteristics to ensure the adaptation of the time-reversed receiver parameters to the channel. For rapidly varying underwater acoustic channels, time-reversed channel estimation is used to reduce the number of periodic channel estimation updates.

[0055] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A cross-medium collaborative sensing underwater acoustic communication method applied to a wave glider platform, characterized in that, The method includes: Wave height parameters are obtained using a wave height meter mounted on the wave glider platform, and cross-media collaborative estimation of sea surface dynamic parameters is performed based on the correlation between the wave height parameters and the dynamic characteristics of sea surface waves. For slowly varying underwater acoustic channels, the channel update time of the time-reversal underwater acoustic communication receiver is set using the stationary time corresponding to the wave height parameter, and the underwater acoustic channel characteristics are periodically acquired to ensure the adaptation of the time-reversal receiver parameters to the channel; assuming the first... The impulse response of the channel is , No. The channel received the symbol information as follows , ,in, This refers to interference noise superimposed on the information signal. This represents a convolution operation; at the receiving end, it is performed according to the wave period. Periodically update the channel estimation to obtain the underwater acoustic channel response. And after reversing the time, we get As a time-reflection preprocessor The coefficients, the received symbol information After time-reflection preprocessor That is, with Perform convolution operation ,in, For time-reverse channel, For the noise interference term of the th channel, Each channel, after passing through its respective time-reflection preprocessor, produces a signal that is... After multi-channel merging, the noise interference term is: The signal is Then, the expressions for the inverted signal and noise interference term in the M channel are respectively: , ,in Number of receiving channels in an underwater acoustic communication system; signal The time-reversed channel is the convolution of the autocorrelation of the channel impulse response and the autocorrelation of the probe signal: After time reversal processing, a single-channel decision feedback equalizer is cascaded to suppress residual multipath. For rapidly changing underwater acoustic channels, time-inverse channel estimation is used to reduce the number of periodic channel estimation updates; the time-inverse channel estimation is embedded in the time-reversal receiver to obtain the time-inverse channel. Estimate In response to the time-inverse channel estimation error Exceeding the preset threshold Channel estimation is performed to update the channel response of the time-inverted processor; the time-inverted channel estimation error Through time-reversal channel Estimation and underwater acoustic channel estimation for each channel The absolute value of the error is obtained by summing over the channel response length L: .

2. The cross-medium collaborative sensing underwater acoustic communication method applied to a wave glider platform according to claim 1, characterized in that, The wave height meter acquires wave height parameters. Wave cycle Estimate the wave period Set threshold According to the wave cycle Value less than or greater than Determine whether the underwater acoustic channel is slowly or rapidly changing, and perform corresponding underwater acoustic communication reception processing.

3. A cross-medium collaborative sensing underwater acoustic communication system applied to a wave glider platform, characterized in that, The system includes: Wave glider platform: The wave glider platform is equipped with a wave height meter to obtain wave height parameters, and performs cross-media collaborative estimation of sea surface dynamic parameters based on the correlation between the wave height parameters and the dynamic characteristics of sea surface waves; Underwater acoustic channel processing unit: configured to, for slowly varying underwater acoustic channels, use the stationary time corresponding to the wave height parameter to set the channel update time of the time-reversed underwater acoustic communication receiver, and periodically acquire underwater acoustic channel characteristics to ensure the adaptation of the time-reversed receiver parameters to the channel; for rapidly varying underwater acoustic channels, use time-reversed channel estimation to reduce the number of periodic channel estimation updates. For slowly varying underwater acoustic channels, the specific components include: Assume the first The impulse response of the channel is , No. The channel received the symbol information as follows , ,in, This refers to interference noise superimposed on the information signal. This represents the convolution operation; At the receiving end, by following the wave cycle Periodically update the channel estimation to obtain the underwater acoustic channel response. And after reversing the time, we get As a time-reflection preprocessor The coefficients, the received symbol information After time-reflection preprocessor That is, with Perform convolution operation ,in, For time-reverse channel, For the first Channel noise interference items, Each channel, after passing through its respective time-reflection preprocessor, produces a signal that is... After multi-channel merging, the noise interference term is: The signal is Then, the expressions for the inverted signal and noise interference term in the M channel are respectively: , ,in Number of receiving channels in an underwater acoustic communication system; signal The time-reversed channel is the convolution of the autocorrelation of the channel impulse response and the autocorrelation of the probe signal: After time reversal processing, a single-channel decision feedback equalizer is cascaded to suppress residual multipath. For fast-changing underwater acoustic channels, the time-inverse channel estimation is embedded into the time-inverse receiver to obtain the time-inverse channel. Estimate In response to the time-inverse channel estimation error Exceeding the preset threshold Channel estimation is performed to update the channel response of the time-inverted processor, wherein the time-inverted channel estimation error is... Through time-reversal channel Estimation and underwater acoustic channel estimation for each channel The absolute value of the error is obtained by summing over the channel response length L: .

4. The cross-medium collaborative sensing underwater acoustic communication system applied to a wave glider platform according to claim 3, characterized in that, The wave height meter acquires wave height parameters. Wave cycle Estimate the wave period Set threshold According to the wave cycle Value less than or greater than Determine whether the underwater acoustic channel is slowly or rapidly changing, and perform corresponding underwater acoustic communication reception processing.

Images