Data transmission method, device and equipment of underwater acoustic communication network and medium

Abstract

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

Description

Technical Field

[0001] The present invention relates to the field of underwater acoustic communication technology, and particularly relates to a data transmission method, device, equipment and medium for an underwater acoustic communication network. Background Art

[0002] With the continuous development of ocean research, underwater acoustic sensor networks (UASNs) have become one of the research hotspots in the academic community. Underwater acoustic sensor networks are a key technology for data collection and transmission in underwater environments, and are widely used in fields such as environmental monitoring, disaster prevention, and resource exploration. However, the complex underwater acoustic channel can cause serious packet loss and bit errors in the sensor network. Traditional reliable data transmission schemes usually rely on redundancy and retransmission mechanisms to ensure the reliability of data transmission. However, these methods often prioritize the reliability of transmission while ignoring energy consumption and the per-hop delay caused by redundant data. Therefore, how to maximize the reliability of data transmission while reducing redundancy has become a key challenge. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a data transmission method, device, equipment and medium for an underwater acoustic communication network, which can reduce the number of redundant packets while improving transmission reliability. The specific scheme is as follows:

[0004] In a first aspect, the present application discloses a data transmission method for an underwater acoustic communication network, which is applied to a sending end in an underwater acoustic sensor network system, and includes:

[0005] Obtain an 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;

[0006] Encode the first encoded data packet using a forward error correction code at the physical layer to generate a second encoded data packet, and send the second encoded data packet to a receiving end in the underwater acoustic sensor network system to obtain an acknowledgment data packet returned by the receiving end;

[0007] According to the acknowledgment data packet, dynamically adjust the parameter configurations of the rateless code and the forward error correction code using a preset multi-objective genetic algorithm to determine optimal coding parameters, and transmit the original data packet based on the optimal coding parameters.

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

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

[0010] Sending the second encoded data packet to the receiving end in the underwater acoustic sensor network system so that the receiving end sequentially decodes 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] Obtaining the probability result of successfully decoding the second encoded data packet determined by the receiving end through the decoding success probability determination formula; 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, is the probability that the receiving end restores i successfully received data packets into a matrix of rank K, is the probability that the receiving end successfully receives i data packets from the second encoded data packet.

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

[0016] Determining the expected per-hop delay, expected throughput, and total energy consumption in a single data transmission process respectively through corresponding calculation formulas according to the acknowledgment data packet;

[0017] Taking the expected per-hop delay, the expected throughput, and the total energy consumption as optimization metrics, and dynamically adjusting the parameter configurations of the rateless code and the forward error correction code using a preset multi-objective genetic algorithm to determine the optimal coding parameters.

[0018] Optionally, the calculation formula for the expected per-hop delay is:

[0019] ;

[0020] where, is the probability of successfully decoding the second encoded data packet, N is the number of the second encoded data packets sent by the sending end, K is the number of data packets received by the receiving end, len is the byte length of the data packet, is the transmission time of each byte, is the transmission time of the confirmation data packet, is the propagation delay, is the total number of data packets transmitted after the first retransmission;

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

[0022] ;

[0023] n is the number of symbols included in the second encoded data packet, and t is the number of error symbols appended by the RS code;

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

[0025] ;

[0026] where, is the energy consumption per byte.

[0027] Optionally, the optimization objectives of the preset multi-objective genetic algorithm include a linear objective function and a combination of constraint conditions,

[0028] The linear objective function is ; the combination of constraint conditions is ; where, is the values of variables N and t when taking the minimum value; is the weight factor of the expected per-hop delay, is the weight factor of the expected throughput, is the weight factor of the total energy consumption.

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

[0030] In a second aspect, the present application discloses a data transmission device for an underwater acoustic communication network, which is applied to a sending end in an underwater acoustic sensor network system and includes:

[0031] A first encoding module, configured to obtain an 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;

[0032] A second encoding module, configured to encode the first encoded data packet using a forward error correction code at the physical layer to generate a second encoded data packet, and send the second encoded data packet to a receiving end in the underwater acoustic sensor network system to obtain a confirmation data packet returned by the receiving end;

[0033] A parameter adjustment module, configured to dynamically adjust the parameter configurations of the rateless code and the forward error correction code according to the confirmation data packet by using a preset multi-objective genetic algorithm, so as to determine optimal coding parameters, and transmit the original data packet based on the optimal coding parameters.

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

[0035] In a fourth aspect, the present application discloses a computer-readable storage medium, which is used to store 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] The present application provides a data transmission method for an underwater acoustic communication network, which is applied to a sending end in an underwater acoustic sensor network system, and includes: obtaining an original data packet to be transmitted, and encoding the original data packet by using a rateless code at the MAC layer to generate a first encoded data packet; encoding the first encoded data packet by 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 a receiving end in the underwater acoustic sensor network system to obtain a confirmation data packet returned by the receiving end; dynamically adjusting the parameter configurations of the rateless code and the forward error correction code according to the confirmation data packet by using a preset multi-objective genetic algorithm to determine optimal coding parameters, and transmitting the original data packet based on the optimal coding parameters.

[0037] The beneficial technical effects of the present application are as follows: First, at the MAC layer, the original data packet is encoded by using a rateless code, which can achieve error correction at the data packet level and handle the problem of packet loss; then, at the physical layer, the first encoded data packet generated by encoding with the rateless code is subjected to symbol-level error correction by using a forward error correction code, reducing the influence of bit errors in the data packet. In this way, cross-layer coding is achieved through this combination, reducing the number of redundant packets while improving transmission reliability. In addition, the channel state information during the transmission process can be obtained through the confirmation data packet returned by the receiving end, and the coding parameters can be dynamically adjusted according to the channel state information by using a preset multi-objective genetic algorithm, and the best parameter configurations of the rateless code and the forward error correction code can be selected. Transmitting data based on the optimal coding parameters can ensure that the system achieves the best balance among transmission delay, throughput, and energy consumption.

[0038] In addition, a data transmission device, equipment, and storage medium provided by the present application corresponding to the above data transmission method for an underwater acoustic communication network have the same effects. Description of the Drawings

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to the provided drawings.

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

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

[0042] Figure 3 It is a schematic diagram of the pseudocode of an optimization algorithm disclosed in this application;

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

[0044] Figure 5 It is a structural diagram of an electronic device disclosed in this application. Specific embodiments

[0045] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0046] In recent years, the country has vigorously developed the marine cause. As an important part of underwater wireless communication, underwater acoustic communication (UAC) and network technology have attracted wide attention. Underwater acoustic communication not only has great applications in the civilian field, but also plays an important role in many aspects such as the commercial and military fields. With the improvement of the scientific and technological levels of major marine powers, the process of building an integrated space-air-ground-sea-submarine network is irresistible. At present, the information transmission and integration technologies of space-air-ground-sea have been relatively mature, and the demand for marine information is becoming increasingly strong. To improve the ability to obtain marine information, the development of underwater acoustic communication and network technology is indispensable.

[0047] Underwater Acoustic Sensor Networks (UASNs) are underwater subnets that, within a certain underwater area, acquire underwater information through various sensor nodes, conduct acoustic communication and networking among underwater nodes, and finally, through specific nodes, incorporate the information obtained in the coverage area back into the onshore conventional network in the form of radio and wire, and send it to the observer.

[0048] In the early construction of UASNs, due to the significant attenuation of radio waves during underwater propagation, the strategy of directly migrating terrestrial wireless ad-hoc networks to the underwater environment could not be realized. Currently, sound waves are widely regarded as the only medium for medium- and long-distance transmission in underwater communication, but the unique propagation characteristics of sound in water require it to have a certain adaptability to the characteristics of the marine environment. At the same time, since the network is usually powered by batteries, there should be a limit on the overall operating energy consumption of the network. Moreover, since underwater acoustic sensor networks are tasked with data transmission, in order to transmit data in a timely manner, it is necessary to minimize data transmission delay and increase throughput while following appropriate network protocols.

[0049] Based on these challenges, for UASNs, it is crucial to reasonably balance the relationship among energy consumption, data transmission throughput, and delay.

[0050] Existing reliable data transmission protocols usually adopt redundancy and retransmission mechanisms to improve data transmission reliability, such as Forward Error Correction (FEC) coding and Auto Repeat Request (ARQ) mechanisms. Forward error correction coding detects and corrects errors by adding redundant bits, while the automatic repeat request mechanism improves transmission reliability by retransmitting lost or incorrect data packets. In the prior art, 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 method may lead to unnecessary energy waste or delay in some scenarios, so how to balance these factors becomes a key issue.

[0051] Currently, a Recursive Online Fountain Code With Limited Feedback (ROFC-LF) scheme has been proposed. It designs a new underwater data transmission mechanism. The sender sends encoding 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 to inform its current decoding state. After reaching the largest connected component, the sender starts to send encoding packets with a degree of 1 until all the original data packets in this connected component are successfully decoded. In the completion stage, the receiver calculates the optimal degree based on the decoding state and feeds it back to the sender. The sender adjusts the encoding strategy according to the feedback and continues to send encoding packets until all the original data packets are successfully recovered. To reduce the number of feedback packets, ROFC-LF introduces a feedback threshold. When the decoding progress is less than a certain threshold, no feedback packet is sent.

[0052] It can be seen that based on the ARQ mechanism, the above scheme proposes a Recursive Online Fountain Code (ROFC-LF) scheme. Its goal is to reduce the transmission of useless encoding packets and the number of feedback packets, thereby improving the channel utilization rate and reducing energy consumption. Compared with the traditional Online Fountain Code (OFC), ROFC-LF has been improved in terms of encoding efficiency and feedback optimization. By setting a decoding progress threshold, feedback packets are only sent when there is a significant change in the decoding state, which greatly reduces the number of feedback packets and thus improves the channel utilization efficiency.

[0053] However, in a complex underwater environment, simply using fountain codes may not be sufficient to cope with the harsh channel environment. At the same time, for a channel with strong time-variability, the method proposed above may still need to send feedback packets frequently, which cannot well reduce the resources consumed by the system, and the increased feedback transmission time is difficult to meet the requirements of tasks with high timeliness.

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

[0055] Before introducing this application, for better understanding of this application, first, relevant terms used in this application are explained.

[0056] (1) Hop-by-hop delay: In an underwater acoustic sensor network, there are often multiple data receiving and sending nodes. The time consumed during the process of data being relayed through each node and transmitted from one node to another is called the hop-by-hop delay.

[0057] (2) Reed-Solomon (RS) codes and Luby Transform (LT) codes: RS codes are a type of forward error correction coding widely used in digital communication, capable of detecting and correcting a certain number of symbol errors during transmission; LT codes are rateless fountain codes that can generate an infinite number of coded symbols, thus enabling data transmission over unreliable channels. LT codes are flexible and suitable for channels with a high packet loss rate.

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

[0059] (4) Channel state information: Channel state information refers to the channel attributes of a communication link, which 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, etc.

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

[0061] An embodiment of the present invention discloses a data transmission method for an underwater acoustic communication network, which is applied to the sending end in an underwater acoustic sensor network system. Refer to 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 an embodiment of the present application, the original data packet is a data packet to be transmitted generated from the original data collected by underwater sensors. First, the sending end generates N first encoded data packets using a rateless code at the MAC layer. In a specific implementation, the rateless code is an LT code.

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

[0065] Step S12: Encode the first encoded data packet using a forward error correction code 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 an acknowledgement packet returned by the receiving end.

[0066] In the embodiment of the present application, based on cross-layer coding, a forward error correction code is used at the physical layer to continue encoding each first encoded data packet to generate a second encoded data packet. In a 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 symbols from m original data symbols, where k is the number of additional parity symbols. In the embodiment of the present application, 2t additional symbols are appended to the first encoded data packet through RS coding to enhance these data packets. During the decoding process, if an error occurs during transmission, the decoder uses the k parity symbols to identify and correct these errors. The decoder has the ability to recover the message in the case of at most t error symbols, where t = k / 2.

[0068] Furthermore, the sending end sends the generated second encoded data packet to the receiving end, and the receiving end correspondingly decodes the data packet using RS and LT decoding methods, and finally feeds back an acknowledgement packet (Acknowledgement, ACK) to the sending end. It can be understood that after receiving the second encoded data packet, the receiving end first decodes it through RS decoding at the physical layer, performs 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 decoded through LT decoding at the MAC layer, and packet-level recovery is performed based on LT encoding and decoding to handle the packet loss problem. Through this combination, the number of redundant packets can be reduced while improving the transmission reliability.

[0069] Specifically, send the second encoded data packet to the receiving end in the underwater acoustic sensor network system so that the receiving end sequentially decodes the second encoded data packet using RS decoding method and LT decoding method to generate the acknowledgement packet.

[0070] Step S13: According to the acknowledgment packet, use a preset multi-objective genetic algorithm to dynamically adjust the parameter configurations of the rateless code and the forward error correction code to determine the optimal coding parameters, and transmit the original packet based on the optimal coding parameters.

[0071] After each round of transmission, the sender can determine the number of packets successfully received by the receiver according to the acknowledgment packet. Then, the sender updates its estimated channel state information based on the received feedback. In the embodiments of the present application, based on the cross-layer coding scheme, a preset multi-objective genetic algorithm is used to dynamically optimize the cross-layer coding strategy. Through the channel state information obtained during the transmission process, the preset multi-objective genetic algorithm can select the best parameter configurations for RS and LT coding to ensure the best balance among system throughput, energy consumption, and hop-by-hop delay. In a specific implementation manner, the preset multi-objective genetic algorithm includes: the NSGA-II algorithm.

[0072] As Figure 2 shown is a schematic diagram of the reliability transmission process implemented based on cross-layer coding. In the work, both RS codes and LT codes are introduced. By combining the RS code in the physical layer and the LT code in the MAC layer, bit-level and packet-level error recovery are achieved to improve the successful reception rate of packets and enhance the robustness of the communication process. In addition, the NSGA-II algorithm is used to generate the optimal coding parameters, including the transmission window N of the LT code and the number of parity symbols k (k = 2t) in the RS code.

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

[0074] The beneficial technical effects of this application are as follows: First, at the MAC layer, the rateless code is used to encode the original data packet, which can achieve error correction at the data packet level and handle packet loss problems. Then, at the physical layer, the first encoded data packet generated by encoding with the rateless code is corrected for symbol-level errors using the forward error correction code, reducing the impact of bit errors in the data packet. In this way, cross-layer coding is achieved through this combination, reducing the number of redundant packets while improving transmission reliability. In addition, the channel state information during the transmission process can be obtained through the acknowledgment data packet returned by the receiving end, and the encoding parameters can be dynamically adjusted according to the channel state information using the preset multi-objective genetic algorithm, and the optimal parameter configuration of the rateless code and the forward error correction code can be selected. Based on the optimal encoding parameters for data transmission, it is possible to ensure that the system achieves the best balance among transmission delay, throughput, and energy consumption.

[0075] Based on the above embodiments, it can be seen that RS coding and LT coding are respectively applied to the physical layer and the MAC layer. In this embodiment, the symbol-level error correction based on RS encoding and decoding, and the packet-level recovery based on LT encoding and decoding are described in detail.

[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 the RS code. Then the packet loss rate can be expressed as:

[0077] ;

[0078] where is the number of symbols containing errors, and t is half of the number of parity symbols k. Since the RS code can only recover t error symbols, a data packet containing more than t error symbols will be regarded as a lost packet. Assume that each symbol has bits, then the symbol error rate can be expressed as: ; where is the bit error rate.

[0079] According to the above formula, the actual packet loss rate calculation formula can be expressed as:

[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 of the data packet, 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. In the case of K original packets, a necessary condition for successful decoding at the receiving end is to receive K linearly independent encoded packets. When the receiving end successfully receives M packets, the probability of recovering a matrix of rank K from these packets is:

[0083] ;

[0084] Then, for the N packets generated by LT codes, the probability that the receiving end successfully receives i packets is:

[0085] ;

[0086] Combining the above two formulas, when the sending end transmits N packets, the probability that the receiving end successfully decodes the original information can be obtained from the following decoding success probability determination formula. Using this probability formula, the sending end can calculate and obtain a dynamic balance between reliability and data transmission redundancy.

[0087] ;

[0088] where N is the number of the second encoded packets sent by the sending end, is the probability that the receiving end recovers a matrix of rank K from the successfully received i packets, is the probability that the receiving end successfully receives i packets from the second encoded packets.

[0089] Based on the foregoing embodiments, it can be seen that the efficiency of the reliability transmission scheme through cross-layer coding is significantly affected by the parameter selection in LT codes and RS codes. Therefore, in order to further improve the data transmission efficiency, in this embodiment, a multi-objective optimization algorithm based on NSGA-II is used to jointly optimize the parameters used in the two coding methods at the MAC layer and the physical layer. 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 that represent the best trade-off 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 should be noted that the relationship between delay and throughput is not simply negatively correlated.

[0090] Specifically, mainly by online changing the proportion of parity symbols in the RS code and the redundancy of the LT code, that is, dynamically adjusting the values of the coding parameters N and t, so as to reduce the size of the coded packets, thereby achieving a reduction in the energy consumed by the system to transmit data. And at the receiving end, by estimating the packet loss rate, the estimated system transmission delay and overall throughput are calculated, and the parameters of the RS code and LT code are dynamically adjusted in combination with the energy consumed by the system, so that the overall energy consumption, efficiency and delay of the UASNs system can reach an excellent level, achieving an optimal balance among transmission delay, throughput and energy consumption.

[0091] During the transmission process, the sender can check the number of packets successfully received in the current transmission round through the feedback acknowledgment packets, so as to estimate the packet loss rate. Exemplarily, in this embodiment, the Exponentially Weighted Moving-Average (EWMA) method is used to iteratively estimate the true channel state information, and the calculation method for estimating the packet loss rate is as follows:

[0092] ;

[0093] where is the estimated value of the packet loss rate in the current round, is the predefined weighting factor. Then the estimated bit error rate can be calculated using the actual packet loss rate calculation formula disclosed in the foregoing embodiment.

[0094] Furthermore, according to the acknowledgment packets, the expected per-hop delay, expected throughput and total energy consumption in a data transmission process are respectively determined through corresponding calculation formulas; in the first specific implementation manner, assuming the length of the data packet is len bytes, considering the decoding failure rate, the expected per-hop delay is: ;

[0095] where is the probability of successfully decoding the second coded packet, N is the number of the second coded packets sent by the sender, K is the number of packets received by the receiver, len is the byte length of the data packet, is the transmission time of each byte, is the transmission time of the acknowledgment packet, is the propagation delay, is the total number of packets transmitted after the first retransmission; since when implementing reliable data transmission based on cross-layer coding, the decoding failure rate is usually very low, so can be approximately regarded as 1.

[0096] According to the above-obtained transmission delay, the expected throughput during data transmission is:

[0097] ;

[0098] Among them, n is the number of symbols included in the second encoded data packet, t is the number of error symbols appended by the RS code; N represents the number of initial packets of the LT code. When data is transmitted, after each data packet is encoded by the RS code at the physical layer, only a smaller part n of (n - 2t) constitutes the information part. Further, the total energy consumed in one transmission process is: ; Among them, is the energy consumption per byte, is approximately equal to the total number of data packets transmitted in one transmission.

[0099] It should be noted that, in order to obtain a lower bit error rate and thus reduce the redundancy of the LT code (which helps to reduce latency and energy consumption), the proportion of the check symbol k in the RS code can be increased. However, this will reduce the proportion of message symbols and lower the throughput efficiency. Therefore, weighing among these three factors is the key to this multi-objective optimization problem. In order to obtain K in the LT code and n in the RS code, an optimal coding strategy needs to be found by determining the values of N and t (where 2t = k), and the optimization objective in this embodiment can be expressed as:

[0100] ;

[0101] .

[0102] In a specific implementation manner, the optimal value of is found by using a linear objective function, and in the optimization objective is further expressed as ; Among them, is the value of variables N and t when obtains the minimum value; is the weight factor of the expected hop-by-hop delay, is the weight factor of the expected throughput, is the weight factor of the total consumed energy.

[0103] As Figure 3 shown is a schematic diagram of the pseudocode of an optimization algorithm provided exemplarily based on the steps in the foregoing embodiment. It can be seen that a multi-objective optimization algorithm based on NSGA-II is adopted to dynamically adjust the values of the coding parameters N and t, achieving an optimal balance among transmission delay, throughput, and energy consumption.

[0104] Correspondingly, the embodiment of the present application also discloses a data transmission device for an underwater acoustic communication network, which is applied to the sending end in an underwater acoustic sensor network system. Referring to Figure 4 shown, this device includes:

[0105] The first encoding module 11 is configured to obtain the original data packet to be transmitted, and encode the original data packet using the rateless code at the MAC layer to generate a first encoded data packet;

[0106] The second encoding module 12 is configured to encode the first encoded data packet using the forward error correction code 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 an acknowledgment packet returned by the receiving end;

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

[0108] Among them, for the more specific working processes of the above-mentioned various modules, reference can be made to the corresponding content disclosed in the foregoing embodiments, and details will not be elaborated herein.

[0109] Thus, through the above solution of this embodiment, the sending end applied to the underwater acoustic sensor network system includes: obtaining the original data packet to be transmitted, and encoding the original data packet using the rateless code at the MAC layer to generate a first encoded data packet; encoding the first encoded data packet using the 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 in the underwater acoustic sensor network system to obtain an acknowledgment packet returned by the receiving end; dynamically adjusting the parameter configurations of the rateless code and the forward error correction code using a preset multi-objective genetic algorithm according to the acknowledgment 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 the rateless code, which can achieve error correction at the data packet level and handle the problem of packet loss; then, at the physical layer, the first encoded data packet generated by encoding with the rateless code is corrected for symbol-level errors using the forward error correction code to reduce the influence of bit errors in the data packet. In this way, cross-layer encoding is achieved through this combination, reducing the number of redundant packets while improving transmission reliability. In addition, the channel state information during the transmission process can be obtained through the acknowledgment packet returned by the receiving end, and the encoding parameters can be dynamically adjusted according to the channel state information using a preset multi-objective genetic algorithm to select the best parameter configurations of the rateless code and the forward error correction code. Transmitting data based on the optimal encoding parameters can ensure that the system achieves the best balance among transmission delay, throughput, and energy consumption.

[0111] Further, an embodiment of the present application also discloses an electronic device. Figure 5 FIG. 20 is a structural diagram of an electronic device 20 shown according to an exemplary embodiment. The content in the figure should not be regarded as any limitation on the scope of use of the present application.

[0112] Figure 5 FIG. 6 is a schematic structural diagram of an electronic device 20 provided by an embodiment of the present application. The electronic device 20 may specifically 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. Among them, the memory 22 is used to store a computer program, and the computer program 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 is any communication protocol applicable to the technical solution of the present application, and no specific limitation is imposed on it here; the input / output interface 25 is used to obtain external input data or output data to the outside, and its specific interface type can be selected according to specific application needs, and no specific limitation is made here.

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

[0115] Among them, the operating system 221 is used to manage and control each hardware device and the computer program 222 on the electronic device 20, and it can be Windows Server, Netware, Unix, Linux, etc. In addition to the computer program that can be used to complete the data transmission method of the underwater acoustic communication network executed by the electronic device 20 disclosed in any of the foregoing embodiments, the computer program 222 may further include a computer program that can be used to complete other specific tasks.

[0116] Further, the embodiments of the present application also disclose a computer-readable storage medium, where the computer-readable storage medium includes a random access memory (RAM), internal memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, registers, a hard disk, a magnetic disk, or an optical disc, or any other form of storage medium known in the technical field. Among them, when the computer program is executed by a processor, it implements the data transmission method of the foregoing underwater acoustic communication network. For the specific steps of this method, reference can be made to the corresponding content disclosed in the foregoing embodiments, and details will not be repeated here.

[0117] The various embodiments in this specification are described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and reference can be made to the description of the method part for the relevant parts.

[0118] The steps of the data transmission method or algorithm of the underwater acoustic communication network described in combination with the embodiments disclosed in this article can be directly implemented by hardware, a software module executed by a processor, or a combination of the two. The software module can be placed in a random access memory (RAM), internal memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the technical field.

[0119] Finally, it should also be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover a non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0120] The above has introduced in detail a data transmission method, device, equipment and medium of an underwater acoustic communication network. In this article, specific examples are used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A data transmission method for an underwater acoustic communication network, characterized in that: The transmitter used in the underwater acoustic sensor network system includes: Acquire an 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; Encoding the first coded data packet using a forward error correction code at a physical layer to generate a second coded data packet, and sending the second coded data packet to a receiving end in the underwater acoustic sensor network system to obtain a confirmation data packet returned by the receiving end; According to the confirmation data packet, the parameter configuration of the rateless code and the forward error correction code is dynamically adjusted using a preset multi-objective genetic algorithm to determine optimal coding parameters, and the original data packet is transmitted based on the optimal coding parameters.

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; Correspondingly, sending the second encoded data packet to the receiving end in the underwater acoustic sensor network system to obtain a confirmation data packet returned by the receiving end includes: The second coded data packet is sent to a receiving end in the underwater acoustic sensor network system, so that the receiving end sequentially decodes the second coded data packet using an RS decoding method and an LT decoding method to generate the confirmation data packet.

3. The data transmission method of the underwater acoustic communication network according to claim 2, characterized in that: The obtaining of the confirmation data packet returned by the receiving end comprises: Obtain a probability result of successfully decoding the second encoded data packet determined by the receiving end through a decoding success probability determination formula; the decoding success probability determination formula is: ； Wherein, N is the number of the second coded data packets sent by the sending end, is the probability that the receiving end recovers a matrix of rank K from the i successfully received data packets, is 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 method of 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 confirmation data packet to determine the optimal coding parameters includes: Determine the expected hop-by-hop delay, expected throughput and total energy consumed in a data transmission process according to the confirmation data packet by using corresponding calculation formulas; The expected hop-by-hop delay, the expected throughput and the total energy consumption are used as optimization indicators, and 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 optimal coding parameters.

5. The data transmission method of the underwater acoustic communication network according to claim 4, characterized in that: The calculation formula of the expected hop-by-hop delay is: ； in, is the probability of successfully decoding the second coded data packet, N is the number of the second coded data packets sent by the sending end, K is the number of data packets received by the receiving end, len is the byte length of the data packet, is the transmission time for each byte, is the transmission time of the confirmation data packet, is the propagation delay, is the total number of packets transmitted after the first retransmission; The calculation formula of the expected throughput is: ； is the number of symbols contained in the second coded data packet, The number of error symbols added to the RS code; The calculation formula of the total energy consumption is: ； in, is the energy consumption per byte.

6. The data transmission method of the underwater acoustic communication network according to claim 5, characterized in that: The optimization objective of the preset multi-objective genetic algorithm includes a linear objective function and a constraint condition combination. The linear objective function is The constraint combination is ;in, for The values ​​of variables N and t when the minimum value is obtained; is the weight factor of the expected hop-by-hop delay, is the weight factor of the expected throughput, is the weight factor of the total energy consumption.

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

8. A data transmission device for an underwater acoustic communication network, characterized in that: The transmitter used in the underwater acoustic sensor network system includes: A first encoding module, used for acquiring an original data packet to be transmitted, and encoding the original data packet using a rateless code at a MAC layer to generate a first encoded data packet; A second encoding module is used to encode the first encoded data packet using a forward error correction code at a physical layer to generate a second encoded data packet, and send the second encoded data packet to a receiving end in the underwater acoustic sensor network system to obtain a confirmation data packet returned by the receiving end; A parameter adjustment module is used to dynamically adjust the parameter configuration of the rateless code and the forward error correction code according to the confirmation data packet using a preset multi-objective genetic algorithm to determine optimal coding parameters, and transmit the original data packet based on the optimal coding parameters.

9. 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, and the computer program 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 7.

10. A computer-readable storage medium, characterized in that: Used to store computer programs; wherein the computer programs, when executed by the processor, implement the data transmission method of the underwater acoustic communication network as described in any one of claims 1 to 7.

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