A data transmission method, device, equipment and medium of an underwater acoustic communication network

Abstract

The application discloses a data transmission method and device of an underwater acoustic communication network, an equipment and a medium, and relates to the technical field of underwater acoustic communication. The method is applied to a sending end in an underwater acoustic sensor network system, and comprises the following steps: obtaining an original data packet to be transmitted, and encoding the original data packet by using a rateless code at a MAC layer to generate a first encoded data packet; encoding the first encoded data packet by using a forward error correction code at a physical layer to generate a second encoded data packet; sending the second encoded data packet to a receiving end, and obtaining an acknowledgement data packet returned by the receiving end; dynamically adjusting the parameter configuration of the rateless code and the forward error correction code by using a preset multi-objective genetic algorithm according to the acknowledgement data packet, so as to determine optimal encoding parameters, and transmitting the original data packet based on the optimal encoding parameters. By means of the technical scheme, the bit error and the packet loss in the underwater channel can be solved, and the packet recovery rate and the transmission reliability are improved.

Description

Technical Field

[0001] This invention relates to the field of underwater acoustic communication technology, and in particular to a data transmission method, apparatus, equipment and medium for underwater acoustic communication networks. Background Technology

[0002] With the continuous development of marine research, Underwater Acoustic Sensor Networks (UASNs) have become a research hotspot in academia. UASNs are a key technology for data acquisition and transmission in underwater environments, widely used in environmental monitoring, disaster prevention, and resource exploration. However, complex underwater acoustic channels can lead to severe packet loss and bit errors in sensor networks. Traditional reliable data transmission schemes typically rely on redundancy and retransmission mechanisms to ensure data transmission reliability. However, these methods often prioritize transmission reliability while neglecting energy consumption and hop-by-hop delays caused by redundant data. Therefore, maximizing data transmission reliability while reducing redundancy has become a critical challenge. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide a data transmission method, apparatus, device, and medium for underwater acoustic communication networks, which can improve transmission reliability while reducing the number of redundant packets. The specific solution is as follows:

[0004] In a first aspect, this application discloses a data transmission method for an underwater acoustic communication network, applied to the transmitting end of an underwater acoustic sensor network system, comprising:

[0005] The original data packet to be transmitted is obtained, and the original data packet is encoded using a rateless code at the MAC layer to generate a first encoded data packet;

[0006] The first encoded data packet is encoded using forward error correction codes at the physical layer to generate a second encoded data packet, and the second encoded data packet is sent to the receiving end in the underwater acoustic sensor network system to obtain the acknowledgment data packet returned by the receiving end.

[0007] Based on the confirmed data packet, a preset multi-objective genetic algorithm is used to dynamically adjust the parameter configuration of the rateless code and the forward error correction code to determine the optimal encoding parameters, and the original data packet is transmitted based on the optimal encoding parameters.

[0008] Optionally, the rateless code is an LT code, and the forward error correction code is an RS code;

[0009] Accordingly, sending the second encoded data packet to the receiving end of the underwater acoustic sensor network system to obtain the acknowledgment data packet returned by the receiving end includes:

[0010] The second encoded data packet is sent to the receiving end in the underwater acoustic sensor network system so that the receiving end can sequentially decode the second encoded data packet using RS decoding and LT decoding to generate the acknowledgment data packet.

[0011] Optionally, obtaining the acknowledgment data packet returned by the receiving end includes:

[0012] Obtain the probability result of successfully decoding the second encoded data packet, as determined by the decoding success probability determination formula at the receiving end; the decoding success probability determination formula is:

[0013] ;

[0014] Where N is the number of the second encoded data packets sent by the sending end. Let be the probability that the receiving end can reconstruct a matrix of rank K from the i successfully received data packets. Let i be the probability that the receiving end successfully receives i data packets from the second encoded data packet.

[0015] Optionally, the step of dynamically adjusting the parameter configurations of the rateless code and the forward error correction code using a preset multi-objective genetic algorithm based on the confirmed data packet to determine the optimal coding parameters includes:

[0016] Based on the confirmed data packets, the expected hop-by-hop delay, expected throughput, and total energy consumption in a single data transmission process are determined using the corresponding calculation formulas.

[0017] Using the expected hop-by-hop delay, the expected throughput, and the total energy consumed as optimization indicators, a preset multi-objective genetic algorithm is used to dynamically adjust the parameter configuration of the rateless code and the forward error correction code to determine the optimal coding parameters.

[0018] Optionally, the formula for calculating the expected hop-by-hop delay is:

[0019] ;

[0020] in, The probability of successfully decoding the second encoded data packet is defined as follows: N is the number of second encoded data packets sent by the sending end, K is the number of data packets received by the receiving end, and len is the length of the data packet in bytes. The transmission time for each byte, The transmission time of the confirmation data packet. To delay the spread, This represents the total number of data packets transmitted after the first retransmission.

[0021] The formula for calculating the expected throughput is as follows:

[0022] ;

[0023] n is the number of symbols contained in the second encoded data packet, and t is the number of error symbols added to the RS code;

[0024] The formula for calculating the total energy consumed is:

[0025] ;

[0026] in, Energy consumption per byte.

[0027] Optionally, the optimization objective of the preset multi-objective genetic algorithm includes a linear objective function and a combination of constraints.

[0028] The linear objective function is: The constraint conditions are combined as follows: ;in, for The values ​​of variables N and t when the minimum value is reached; The weighting factor for the expected hop-by-hop delay. The weighting factor for the expected throughput. This is the weighting factor for the total energy consumed.

[0029] Optionally, the preset multi-objective genetic algorithm includes the NSGA-II algorithm.

[0030] Secondly, this application discloses a data transmission device for an underwater acoustic communication network, applied to the transmitting end of an underwater acoustic sensor network system, comprising:

[0031] The first encoding module is used to acquire the original data packet to be transmitted and encode the original data packet using a rateless code at the MAC layer to generate the first encoded data packet.

[0032] The second encoding module is used to encode the first encoded data packet using forward error correction codes at the physical layer to generate a second encoded data packet, and send the second encoded data packet to the receiving end in the underwater acoustic sensor network system to obtain the acknowledgment data packet returned by the receiving end.

[0033] The parameter adjustment module is used to dynamically adjust the parameter configuration of the rateless code and the forward error correction code according to the confirmed data packet using a preset multi-objective genetic algorithm, so as to determine the optimal encoding parameters, and transmit the original data packet based on the optimal encoding parameters.

[0034] Thirdly, this application discloses an electronic device comprising a processor and a memory; wherein the memory is used to store a computer program, which is loaded and executed by the processor to implement the data transmission method of the underwater acoustic communication network as described above.

[0035] Fourthly, this application discloses a computer-readable storage medium for storing a computer program; wherein the computer program, when executed by a processor, implements the data transmission method of the underwater acoustic communication network as described above.

[0036] This application provides a data transmission method for an underwater acoustic communication network, applied to a transmitter in an underwater acoustic sensor network system. The method includes: acquiring a raw data packet to be transmitted, and encoding the raw data packet at the MAC layer using a rateless code to generate a first encoded data packet; encoding the first encoded data packet at the physical layer using a forward error correction code to generate a second encoded data packet, and sending the second encoded data packet to a receiver in the underwater acoustic sensor network system to obtain an acknowledgment data packet returned by the receiver; dynamically adjusting the parameter configurations of the rateless code and the forward error correction code using a preset multi-objective genetic algorithm based on the acknowledgment data packet to determine optimal encoding parameters, and transmitting the raw data packet based on the optimal encoding parameters.

[0037] The beneficial technical effects of this application are as follows: First, at the MAC layer, the original data packet is encoded using a rateless code, which enables packet-level error correction and handles packet loss. Then, at the physical layer, forward error correction (FEC) codes are used to correct symbol-level errors in the first encoded data packet generated using the rateless code, reducing the impact of bit errors in the data packet. In this way, cross-layer coding is achieved through this combination, improving transmission reliability while reducing the number of redundant packets. Furthermore, the channel state information during transmission can be obtained from the acknowledgment data packet returned by the receiver. A pre-defined multi-objective genetic algorithm is used to dynamically adjust the coding parameters based on the channel state information, allowing selection of the optimal parameter configuration for the rateless code and FEC codes. Data transmission based on the optimal coding parameters ensures an optimal balance between transmission delay, throughput, and energy consumption.

[0038] Furthermore, the data transmission device, equipment, and storage medium for an underwater acoustic communication network provided in this application correspond to the data transmission method of the aforementioned underwater acoustic communication network and have the same effect. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0040] Figure 1 This is a flowchart of a data transmission method for an underwater acoustic communication network disclosed in this application;

[0041] Figure 2 This is a schematic diagram of a data transmission process disclosed in this application;

[0042] Figure 3 This is a pseudocode illustration of an optimization algorithm disclosed in this application;

[0043] Figure 4 This is a schematic diagram of the data transmission device structure of an underwater acoustic communication network disclosed in this application;

[0044] Figure 5 This is a structural diagram of an electronic device disclosed in this application. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] In recent years, the nation has vigorously developed its marine industry. As a crucial component of underwater wireless communication, Underwater Acoustic Communication (UAC) and its network technologies have attracted widespread attention. UAC has significant applications not only in the civilian sector but also plays a vital role in numerous other areas, including commerce and the military. With the advancement of technology among major maritime powers, the construction of an integrated air-space-ground-sea network is inevitable. Currently, information transmission and integration technologies across these sectors are relatively mature, and the demand for marine information is increasingly strong. Improving the ability to acquire marine information necessitates the development of UAC and network technologies.

[0047] Underwater acoustic sensor networks (UASNs) are underwater subnets that acquire underwater information through various sensor nodes within a defined underwater area, conduct acoustic communication and networking among the underwater nodes, and finally, through specific nodes, re-integrate the information acquired in the coverage area into the conventional onshore network in the form of radio and wired connections, and transmit it to the observer.

[0048] In the early construction of UASNs, the strategy of directly migrating terrestrial wireless ad hoc networks to the underwater environment was not feasible due to the significant attenuation of radio waves during underwater propagation. Currently, sound waves are widely considered the only medium for medium- to long-range underwater communication, but the unique propagation characteristics of sound underwater necessitate a degree of adaptability to the marine environment. Furthermore, since the network is typically battery-powered, the overall energy consumption of the network should be limited. Moreover, because underwater acoustic sensor networks are responsible for data transmission, timely data transmission requires minimizing data transmission latency and maximizing throughput while adhering to appropriate network protocols.

[0049] Given these challenges, it is crucial for UASNs to find a reasonable balance between energy consumption, data transmission throughput, and latency.

[0050] Existing reliable data transmission protocols typically employ redundancy and retransmission mechanisms to improve data transmission reliability, such as Forward Error Correction (FEC) coding and Automatic Repeat Request (ARQ) mechanisms. FEC detects and corrects errors by adding redundant bits, while ARQ improves reliability by retransmitting lost or erroneous data packets. In current technologies, FEC and ARQ are often combined to form a Hybrid Automatic Repeat Request (HARQ) scheme, which can reduce redundancy while maintaining high reliability. However, this approach may lead to unnecessary energy waste or delays in certain scenarios, making the trade-off between these factors a critical issue.

[0051] Currently, a Recursive Online Fountain Code With Limited Feedback (ROFC-LF) scheme is proposed, which designs a novel underwater data transmission mechanism. The sender transmits encoded packets with a degree of 2 until a feedback packet is received. When the size of the largest connected component in the receiver's decoding graph reaches a certain threshold, the receiver sends feedback to the sender, informing it of the current decoding status. After reaching the largest connected component, the sender begins transmitting encoded packets with a degree of 1 until all original data packets in that connected component are successfully decoded. During the completion phase, the receiver calculates the optimal degree based on the decoding status and feeds it back to the sender. The sender adjusts its encoding strategy based on the feedback and continues transmitting encoded packets until all original data packets are successfully recovered. To reduce the number of feedback packets, ROFC-LF introduces a feedback threshold; when the decoding progress falls below a certain threshold, no feedback packets are sent.

[0052] As can be seen, the above scheme proposes a recursive online fountain code (ROFC-LF) scheme based on the ARQ mechanism. Its goal is to reduce the transmission of useless coded packets and the number of feedback packets, thereby improving channel utilization and reducing energy consumption. Compared to the traditional online fountain code (OFC), ROFC-LF improves coding efficiency and feedback optimization. By setting a decoding progress threshold, feedback packets are only sent when the decoding state changes significantly, which greatly reduces the number of feedback packets and thus improves channel utilization efficiency.

[0053] However, in complex underwater environments, fountain codes alone may not be sufficient to cope with harsh channel conditions. Furthermore, for time-varying channels, the proposed method may still require frequent transmission of feedback packets, failing to effectively reduce system resource consumption. Moreover, the increased feedback transmission time is unsuitable for tasks with high timeliness requirements.

[0054] Therefore, this application provides a data transmission scheme for underwater acoustic communication networks, which can improve transmission reliability while reducing the number of redundant packets through cross-layer coding.

[0055] Before introducing this application, in order to facilitate a better understanding of this application, the relevant terms used in this application will be explained first.

[0056] (1) Hop-by-hop delay: Underwater acoustic sensor networks often contain multiple data receiving and sending nodes. Data can be forwarded through each node as an intermediary. The time consumed in the process of sending data from one node to another is called hop-by-hop delay.

[0057] (2) RS (Reed-Solomon) code and LT (Luby Transform) code: RS code is a forward error correction code widely used in digital communication, which can detect and correct a certain number of symbol errors during transmission; LT code is a non-ratio fountain code that can generate an infinite number of coded symbols, thus enabling data transmission over unreliable channels. LT code is flexible and suitable for channels with high packet loss rates.

[0058] (3) NSGA-II (Non-dominated Sorting Genetic Algorithm II): This is a multi-objective genetic algorithm that can simultaneously optimize multiple conflicting objectives and find Pareto optimal solutions. For cross-layer coding strategy optimization in UASNs, NSGA-II can help find the best balance between throughput, energy consumption, and hop-by-hop delay.

[0059] (4) Channel state information: Channel state information refers to the channel attributes of the communication link. It describes the attenuation factor of the signal on each transmission path, that is, the value of each element in the channel gain matrix, such as signal scattering, environmental attenuation, distance attenuation and other information.

[0060] (5) Cross-layer coding: refers to sharing information between different layers of the network protocol stack to optimize overall system performance. In UASNs, cross-layer coding can achieve high efficiency and reliability of data transmission by combining the coding strategies of the physical layer and the MAC (Medium Access Control) layer.

[0061] This invention discloses a data transmission method for an underwater acoustic communication network, applied to the transmitting end of an underwater acoustic sensor network system. See [link to relevant documentation]. Figure 1 As shown, the method includes:

[0062] Step S11: Obtain the original data packet to be transmitted, and encode the original data packet using a rateless code at the MAC layer to generate a first encoded data packet.

[0063] In this embodiment, the original data packet is a data packet to be transmitted generated using raw data collected by an underwater sensor. First, the sending end generates N first encoded data packets at the MAC layer using a rateless code. In one specific implementation, the rateless code is an LT code.

[0064] LT codes are a special type of fountain code, widely used for efficient data transmission in unreliable channels. As a rateless code, LT codes can generate an infinite number of symbols from raw data. The encoder first generates a distribution d, then selects any d symbols from K raw symbols, performs an XOR operation on them, and encodes them into a single data symbol. After the encoder generates N encoded symbols, the decoder has a high probability of recovering the original information when N is slightly greater than K.

[0065] Step S12: Encode the first encoded data packet using forward error correction codes at the physical layer to generate a second encoded data packet, and send the second encoded data packet to the receiving end in the underwater acoustic sensor network system to obtain the acknowledgment data packet returned by the receiving end.

[0066] In this embodiment, based on cross-layer coding, forward error correction codes are used at the physical layer to continue encoding each first coded data packet, generating a second coded data packet. In one specific implementation, the forward error correction code is an RS code.

[0067] RS code is a forward error correction code widely used in digital communication. It generates a set of errors from m original data symbols. The number of symbols is k, where k is the number of additional check symbols. In this embodiment, the first encoded data packet is enhanced by adding 2t additional symbols to it using RS encoding. During decoding, if an error occurs during transmission, the decoder uses k check symbols to identify and correct these errors. The decoder has the ability to recover the message with a maximum of t error symbols, where t = k / 2.

[0068] Furthermore, the sending end sends the generated second-encoded data packet to the receiving end. The receiving end decodes the data packet using RS and LT decoding methods accordingly, and finally sends an acknowledgment (ACK) data packet back to the sending end. It can be understood that after receiving the second-encoded data packet, the receiving end first decodes it at the physical layer using RS decoding, performing bit-level error correction based on RS encoding and decoding to reduce the impact of bit errors in the data packet. Next, the decoded data packet is passed through the MAC layer for LT decoding, performing data packet-level recovery based on LT encoding and decoding to handle packet loss. This combination improves transmission reliability while reducing the number of redundant packets.

[0069] Specifically, the second encoded data packet is sent to the receiving end in the underwater acoustic sensor network system, so that the receiving end can sequentially decode the second encoded data packet using RS decoding and LT decoding to generate the acknowledgment data packet.

[0070] Step S13: Based on the confirmed data packet, dynamically adjust the parameter configuration of the rateless code and the forward error correction code using a preset multi-objective genetic algorithm to determine the optimal encoding parameters, and transmit the original data packet based on the optimal encoding parameters.

[0071] After each round of transmission, the sending end can determine the number of data packets successfully received by the receiving end based on the acknowledgment data packets, and then update its estimated channel state information based on the received feedback. In this embodiment, a preset multi-objective genetic algorithm is used to dynamically optimize the cross-layer coding strategy based on the cross-layer coding scheme. By using the channel state information obtained during transmission, the preset multi-objective genetic algorithm can select the optimal parameter configuration for RS and LT coding, ensuring that the system achieves the best balance between throughput, energy consumption, and hop-by-hop delay. In one specific implementation, the preset multi-objective genetic algorithm includes the NSGA-II algorithm.

[0072] like Figure 2 The diagram illustrates a reliable transmission process based on cross-layer coding. This work introduces both RS and LT codes, combining the RS code at the physical layer and the LT code at the MAC layer to achieve bit-level and packet-level error recovery, thereby improving the success rate of packet reception and enhancing the robustness of the communication process. Furthermore, the NSGA-II algorithm is used to generate optimal coding parameters, including the transmission window N of the LT code and the number of check symbols k (k=2t) in the RS code.

[0073] This application provides a data transmission method for an underwater acoustic communication network, applied to a transmitter in an underwater acoustic sensor network system. The method includes: acquiring a raw data packet to be transmitted, and encoding the raw data packet at the MAC layer using a rateless code to generate a first encoded data packet; encoding the first encoded data packet at the physical layer using a forward error correction code to generate a second encoded data packet, and sending the second encoded data packet to a receiver in the underwater acoustic sensor network system to obtain an acknowledgment data packet returned by the receiver; dynamically adjusting the parameter configurations of the rateless code and the forward error correction code using a preset multi-objective genetic algorithm based on the acknowledgment data packet to determine optimal encoding parameters, and transmitting the raw data packet based on the optimal encoding parameters.

[0074] The beneficial technical effects of this application are as follows: First, at the MAC layer, the original data packet is encoded using a rateless code, which enables packet-level error correction and handles packet loss. Then, at the physical layer, forward error correction (FEC) codes are used to correct symbol-level errors in the first encoded data packet generated using the rateless code, reducing the impact of bit errors in the data packet. In this way, cross-layer coding is achieved through this combination, improving transmission reliability while reducing the number of redundant packets. Furthermore, the channel state information during transmission can be obtained from the acknowledgment data packet returned by the receiver. A pre-defined multi-objective genetic algorithm is used to dynamically adjust the coding parameters based on the channel state information, allowing selection of the optimal parameter configuration for the rateless code and FEC codes. Data transmission based on the optimal coding parameters ensures an optimal balance between transmission delay, throughput, and energy consumption.

[0075] As can be seen from the above embodiments, RS encoding and LT encoding are applied to the physical layer and MAC layer, respectively. This embodiment provides a detailed description of symbol-level error correction based on RS encoding and decoding, and packet-level recovery based on LT encoding and decoding.

[0076] (1) For symbol-level error correction: At the physical layer, a data packet is divided into several symbols and encoded into a new data packet using RS codes. The data packet loss rate can then be expressed as:

[0077] ;

[0078] in Let t be the number of erroneous symbols, where t is half the number of check symbols k. Since the RS code can only recover t erroneous symbols, packets containing more than t erroneous symbols will be considered lost. Assume each symbol has... The symbol error rate is 1 bit. It can be represented as: ;in This represents the bit error rate.

[0079] Based on the above formula, the actual packet loss rate can be calculated as follows:

[0080] ;

[0081] Where n represents the number of symbols contained in the data packet. The sender uses this formula to calculate the packet loss rate, thereby estimating the redundancy of the LT code.

[0082] (2) For packet-level error correction: At the MAC layer, LT codes are used to perform packet-level encoding. With K original packets, a necessary condition for the receiver to successfully decode is receiving K linearly independent encoded packets. When the receiver successfully receives M packets, the probability of recovering a matrix of rank K from these packets is:

[0083] ;

[0084] For N data packets generated by the LT code, the probability that the receiver successfully receives i data packets is:

[0085] ;

[0086] Combining the first two formulas, when the sender transmits N data packets, the probability that the receiver can successfully decode the original information can be obtained by the following formula for determining the success rate of decoding. Using this probability formula, the sender can calculate a dynamic balance between reliability and data transmission redundancy.

[0087] ;

[0088] Where N is the number of the second encoded data packets sent by the sending end. Let be the probability that the receiving end can reconstruct a matrix of rank K from the i successfully received data packets. Let i be the probability that the receiving end successfully receives i data packets from the second encoded data packet.

[0089] As demonstrated in the foregoing embodiments, the efficiency of reliable transmission schemes using cross-layer coding is significantly affected by the parameter selection in LT and RS codes. Therefore, to further improve data transmission efficiency, this embodiment utilizes the NSGA-II multi-objective optimization algorithm, jointly optimizing the parameters used in both coding methods at the MAC and physical layers. NSGA-II is an evolutionary algorithm for solving multi-objective optimization problems. When multiple conflicting objectives need to be considered simultaneously, this algorithm can find a set of Pareto optimal solutions representing the best trade-offs between the objectives. In the optimization process of determining the optimal coding parameters, the main optimization metrics include hop-by-hop delay, throughput, and energy consumption. It is worth noting that the relationship between delay and throughput is not a simple negative correlation.

[0090] Specifically, this is achieved by dynamically adjusting the proportion of check symbols in the RS code and the redundancy of the LT code online, i.e., dynamically adjusting the values ​​of coding parameters N and t, thereby reducing the size of the encoded packets and thus reducing the energy consumed by the system in transmitting data. Furthermore, at the receiving end, the system transmission delay and overall throughput are estimated by calculating the predicted packet loss rate. Combined with the energy consumption of the system, the parameters of the RS code and LT code are dynamically adjusted to ensure that the overall energy consumption, efficiency, and latency of the UASNs system reach a relatively excellent level, achieving an optimal balance between transmission delay, throughput, and energy consumption.

[0091] During transmission, the sending end can check the number of data packets successfully received in the current transmission round by checking the feedback acknowledgment data packets, thereby estimating the packet loss rate. For example, in this embodiment, the Exponentially Weighted Moving-Average (EWMA) method is used to iteratively estimate the true channel state information. The calculation method for estimating the packet loss rate is as follows:

[0092] ;

[0093] in, This is an estimate of the packet loss rate for the current round. It is a predefined weighting factor. Then, the estimated bit error rate can be calculated using the actual packet loss rate calculation formula disclosed in the aforementioned embodiments.

[0094] Furthermore, based on the confirmed data packets, the expected hop-by-hop delay, expected throughput, and total energy consumption during a single data transmission process are determined using corresponding calculation formulas. In the first specific implementation, assuming the data packet length is len bytes, and considering the decoding failure rate, the expected hop-by-hop delay is: ;

[0095] in, The probability of successfully decoding the second encoded data packet is defined as follows: N is the number of second encoded data packets sent by the sending end, K is the number of data packets received by the receiving end, and len is the length of the data packet in bytes. The transmission time for each byte, The transmission time of the confirmation data packet, To delay the spread, This represents the total number of data packets transmitted after the first retransmission; because the decoding failure rate is typically very low when reliable data transmission is achieved based on cross-layer coding, therefore... It can be approximated as 1.

[0096] Based on the transmission delay obtained above, the expected throughput during data transmission is:

[0097] ;

[0098] Where n is the number of symbols contained in the second encoded data packet, t is the number of error symbols added to the RS code, and N represents the number of initial LT code packets. During data transmission, each data packet is encoded with RS code at the physical layer, and only a small portion n of (n-2t) constitutes the information part. Furthermore, the total energy consumed in one transmission is: ;in, Energy consumption per byte It is approximately equal to the total number of data packets sent in a single transmission.

[0099] It is worth noting that in order to obtain a lower bit error rate and thus reduce the redundancy of the LT code (which helps reduce latency and energy consumption), the proportion of the parity symbol k in the RS code can be increased. However, this will reduce the proportion of message symbols, resulting in a decrease in throughput efficiency. Therefore, the key to this multi-objective optimization problem is to weigh these three factors. To obtain K in the LT code and n in the RS code, it is necessary to find the optimal coding strategy by determining the values ​​of N and t (where 2t=k). The optimization objective in this embodiment can be expressed as:

[0100] ;

[0101] .

[0102] In one specific implementation, a linear objective function is used to find... The optimal value is then the optimization objective. Further expressed as ;in, for The values ​​of variables N and t when the minimum value is reached; The weighting factor for the expected hop-by-hop delay. The weighting factor for the expected throughput. This is the weighting factor for the total energy consumed.

[0103] like Figure 3 The diagram shown is a pseudocode illustration of an optimization algorithm based on the steps exemplified in the foregoing embodiments. It can be seen that the NSGA-II-based multi-objective optimization algorithm dynamically adjusts the values ​​of the encoding parameters N and t, achieving an optimal balance between transmission delay, throughput, and energy consumption.

[0104] Accordingly, this application also discloses a data transmission device for an underwater acoustic communication network, applied to the transmitter in an underwater acoustic sensor network system. See [link to relevant documentation]. Figure 4 As shown, the device includes:

[0105] The first encoding module 11 is used to acquire the original data packet to be transmitted and encode the original data packet using a rateless code at the MAC layer to generate the first encoded data packet.

[0106] The second encoding module 12 is used to encode the first encoded data packet using forward error correction codes at the physical layer to generate a second encoded data packet, and send the second encoded data packet to the receiving end in the underwater acoustic sensor network system to obtain the acknowledgment data packet returned by the receiving end.

[0107] The parameter adjustment module 13 is used to dynamically adjust the parameter configuration of the rateless code and the forward error correction code according to the confirmed data packet using a preset multi-objective genetic algorithm, so as to determine the optimal encoding parameters, and transmit the original data packet based on the optimal encoding parameters.

[0108] For more detailed information on the working process of each of the above modules, please refer to the relevant content disclosed in the foregoing embodiments, which will not be repeated here.

[0109] Therefore, the above-described scheme of this embodiment, applied to the transmitting end of an underwater acoustic sensor network system, includes: acquiring the original data packet to be transmitted, and encoding the original data packet using a rateless code at the MAC layer to generate a first encoded data packet; encoding the first encoded data packet using a forward error correction code at the physical layer to generate a second encoded data packet, and sending the second encoded data packet to the receiving end of the underwater acoustic sensor network system to obtain an acknowledgment data packet returned by the receiving end; dynamically adjusting the parameter configuration of the rateless code and the forward error correction code using a preset multi-objective genetic algorithm based on the acknowledgment data packet to determine the optimal encoding parameters, and transmitting the original data packet based on the optimal encoding parameters.

[0110] The beneficial technical effects of this application are as follows: First, at the MAC layer, the original data packet is encoded using a rateless code, which enables packet-level error correction and handles packet loss. Then, at the physical layer, forward error correction (FEC) codes are used to correct symbol-level errors in the first encoded data packet generated using the rateless code, reducing the impact of bit errors in the data packet. In this way, cross-layer coding is achieved through this combination, improving transmission reliability while reducing the number of redundant packets. Furthermore, the channel state information during transmission can be obtained from the acknowledgment data packet returned by the receiver. A pre-defined multi-objective genetic algorithm is used to dynamically adjust the coding parameters based on the channel state information, allowing selection of the optimal parameter configuration for the rateless code and FEC codes. Data transmission based on the optimal coding parameters ensures an optimal balance between transmission delay, throughput, and energy consumption.

[0111] Furthermore, embodiments of this application also disclose an electronic device, Figure 5 This is a structural diagram of an electronic device 20 according to an exemplary embodiment. The content of the diagram should not be construed as limiting the scope of this application.

[0112] Figure 5 This is a schematic diagram of the structure of an electronic device 20 provided in an embodiment of this application. Specifically, the electronic device 20 may include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 stores a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the data transmission method of the underwater acoustic communication network disclosed in any of the foregoing embodiments.

[0113] In this embodiment, the power supply 23 is used to provide operating voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and external devices, and the communication protocol it follows can be any communication protocol applicable to the technical solution of this application, and is not specifically limited here; the input / output interface 25 is used to acquire external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs, and is not specifically limited here.

[0114] In addition, the memory 22, as a carrier for resource storage, can be a read-only memory, random access memory, disk, or optical disk, etc. The resources stored on it can include an operating system 221, computer programs 222, and data 223, etc. The data 223 can include various types of data. The storage method can be temporary storage or permanent storage.

[0115] The operating system 221 is used to manage and control the various hardware devices on the electronic device 20 and the computer program 222, which may be Windows Server, Netware, Unix, Linux, etc. In addition to including a computer program capable of performing the data transmission method of the underwater acoustic communication network executed by the electronic device 20 as disclosed in any of the foregoing embodiments, the computer program 222 may further include computer programs capable of performing other specific tasks.

[0116] Furthermore, this application also discloses a computer-readable storage medium, which includes random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, magnetic disks, optical disks, or any other form of storage medium known in the art. The computer program, when executed by a processor, implements the aforementioned data transmission method for the underwater acoustic communication network. Specific steps of this method can be found in the corresponding content disclosed in the foregoing embodiments, and will not be repeated here.

[0117] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0118] The steps of the data transmission method or algorithm for the underwater acoustic communication network described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0119] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0120] The data transmission method, apparatus, device, and medium of an underwater acoustic communication network provided by the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A data transmission method for an underwater acoustic communication network, characterized in that, The transmitter used in underwater acoustic sensor network systems includes: The original data packet to be transmitted is obtained, and the original data packet is encoded using a rateless code at the MAC layer to generate a first encoded data packet; The first encoded data packet is encoded using forward error correction codes at the physical layer to generate a second encoded data packet, and the second encoded data packet is sent to the receiving end in the underwater acoustic sensor network system to obtain the acknowledgment data packet returned by the receiving end. Based on the confirmed data packet, a preset multi-objective genetic algorithm is used to dynamically adjust the parameter configurations of the rateless code and the forward error correction code to determine the optimal encoding parameters, and the original data packet is transmitted based on the optimal encoding parameters; wherein, the optimization objective of the preset multi-objective genetic algorithm includes a linear objective function and a combination of constraint conditions. The linear objective function is: The constraint conditions are combined as follows: ;in, for The values ​​of variables N and t when the minimum value is obtained are: N is the number of second encoded data packets sent by the sending end, and t is the number of error symbols added to the RS code; The weighting factor is the expected hop-by-hop delay T. The weighting factor for the expected throughput Th. The weighting factor is the total energy consumed, E; K is the number of data packets received by the receiver. The number of symbols contained in the second encoded data packet.

2. The data transmission method of the underwater acoustic communication network according to claim 1, characterized in that, The rateless code is an LT code, and the forward error correction code is an RS code; Accordingly, sending the second encoded data packet to the receiving end of the underwater acoustic sensor network system to obtain the acknowledgment data packet returned by the receiving end includes: The second encoded data packet is sent to the receiving end in the underwater acoustic sensor network system so that the receiving end can sequentially decode the second encoded data packet using RS decoding and LT decoding to generate the acknowledgment data packet.

3. The data transmission method of the underwater acoustic communication network according to claim 2, characterized in that, The step of obtaining the confirmation data packet returned by the receiving end includes: Obtain the probability result of successfully decoding the second encoded data packet, as determined by the decoding success probability determination formula at the receiving end; the decoding success probability determination formula is: ； Where N is the number of the second encoded data packets sent by the sending end. Let be the probability that the receiving end can reconstruct a matrix of rank K from the i successfully received data packets. Let i be the probability that the receiving end successfully receives i data packets from the second encoded data packet.

4. The data transmission method of the underwater acoustic communication network according to claim 1, characterized in that, The step of dynamically adjusting the parameter configurations of the rateless code and the forward error correction code using a preset multi-objective genetic algorithm based on the confirmed data packet to determine the optimal coding parameters includes: Based on the confirmed data packets, the expected hop-by-hop delay, expected throughput, and total energy consumption in a single data transmission process are determined using the corresponding calculation formulas. Using the expected hop-by-hop delay, the expected throughput, and the total energy consumed as optimization indicators, a preset multi-objective genetic algorithm is used to dynamically adjust the parameter configuration of the rateless code and the forward error correction code to determine the optimal coding parameters.

5. The data transmission method of the underwater acoustic communication network according to claim 4, characterized in that, The formula for calculating the expected hop-by-hop delay is as follows: ； in, The probability of successfully decoding the second encoded data packet is defined as follows: N is the number of second encoded data packets sent by the sending end, K is the number of data packets received by the receiving end, and len is the length of the data packet in bytes. The transmission time for each byte, The transmission time of the confirmation data packet. To delay the spread, This represents the total number of data packets transmitted after the first retransmission. The formula for calculating the expected throughput is as follows: ； The number of symbols contained in the second encoded data packet. The number of error symbols appended to the RS code; The formula for calculating the total energy consumed is: ； in, Energy consumption per byte.

6. The data transmission method of the underwater acoustic communication network according to any one of claims 1 to 5, characterized in that, The preset multi-objective genetic algorithm includes: NSGA-II algorithm.

7. A data transmission device for an underwater acoustic communication network, characterized in that, The transmitter used in underwater acoustic sensor network systems includes: The first encoding module is used to acquire the original data packet to be transmitted and encode the original data packet using a rateless code at the MAC layer to generate the first encoded data packet. The second encoding module is used to encode the first encoded data packet using forward error correction codes at the physical layer to generate a second encoded data packet, and send the second encoded data packet to the receiving end in the underwater acoustic sensor network system to obtain the acknowledgment data packet returned by the receiving end. The parameter adjustment module is used to dynamically adjust the parameter configuration of the rateless code and the forward error correction code based on the confirmed data packet using a preset multi-objective genetic algorithm to determine the optimal encoding parameters, and then transmit the original data packet based on the optimal encoding parameters; wherein, the optimization objective of the preset multi-objective genetic algorithm includes a linear objective function and a combination of constraints. The linear objective function is: The constraint conditions are combined as follows: ;in, for The values ​​of variables N and t when the minimum value is obtained are: N is the number of second encoded data packets sent by the sending end, and t is the number of error symbols added to the RS code; The weighting factor is the expected hop-by-hop delay T. The weighting factor for the expected throughput Th. The weighting factor is the total energy consumed, E; K is the number of data packets received by the receiver. The number of symbols contained in the second encoded data packet.

8. An electronic device, characterized in that, The electronic device includes a processor and a memory; wherein the memory is used to store a computer program, which is loaded and executed by the processor to implement the data transmission method of the underwater acoustic communication network as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, Used to store computer programs; wherein the computer programs, when executed by a processor, implement the data transmission method of the underwater acoustic communication network as described in any one of claims 1 to 6.

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