Underwater acoustic communication balanced decoding method based on recursive chaotic code

Abstract

The invention discloses an underwater acoustic communication balanced decoding method based on a recursive chaotic code, and the method comprises: step 1, inputting an information source information sequence into a recursive chaos model by a coding sending end, carrying out the recursive chaotic coding, generating a symbol frame sequence, generating an information sub-frame, and sending the information sub-frame after signal modulation to a coding receiving end; step 2, the coding receiving end demodulating the received information subframes to generate a symbol sequence, and generating a joint equalization decoding tree according to the number of information fragments in the symbol sequence and the number of information fragments in the information source information sequence; and step 3,the coding receiving end calculating the Euclidean distance between the symbol sequence in each branch and the symbol sequence which is actually received, selecting the branch with the minimum Euclidean distance, and marking the branch as a decoding result. Through the technical scheme provided by the invention, the bit error rate performance of the underwater acoustic communication system is improved, the influence of strong inter-code crosstalk of the underwater acoustic channel and the complexity of a joint equalization decoding algorithm are reduced, and the transmission reliability of the underwater acoustic channel is improved.

Description

technical field [0001] The present application relates to the technical field of underwater acoustic communication, in particular, to an equalization decoding method for underwater acoustic communication based on recursive chaotic codes. Background technique [0002] Underwater acoustic communication technology has been widely used in many fields of national defense and economic construction, such as underwater equipment control of drilling platforms, marine environment monitoring, and information exchange between underwater vehicles. Compared with radio communication, in underwater acoustic communication, the propagation path through which the signal reaches the receiving end is generally not unique, resulting in different delays in arrival time, which in turn causes serious intersymbol interference. At the same time, due to the absorption effect of seawater on sound waves and other reasons, the available bandwidth of the underwater acoustic channel is severely limited. In...

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Problems solved by technology

[0003] In the prior art, the more advanced structure of the receiving end is the Turbo equalization decoding method based on the idea of ​​iterative joint equalization decoding. The interleaving and mixing of information is performed by the interleaver, and the information mixing ability of the interleaver is related to the interleaving length. Finally, only when the interleaving length, that is, the length of the code block is large enough, can the best joint equalized decoding performance be obtained.

[0004] In addition, Turbo equalization decoding adopts an iterative structure, which combines the equalizer and decoder, so that the performance of the decoding method starts to converge only when the SNR is higher than a certain threshold, and when the channel frequency selective fading When it is strong or there is an error in the channel estimation, the SNR threshold of the Turbo equalization decoding method is high, which leads to the unsatisfactory decoding performance of the Turbo equalization decoding method in some strong frequency selective fading or strong time-varying channels.

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