Transform domain underwater acoustic communication method based on chaotic spread spectrum

Abstract

The invention discloses a transform domain underwater acoustic communication method based on chaotic spread spectrum, and the method comprises the following steps: S1, carrying out sampling of an environment channel at a transmitting end and a receiving end, obtaining an environment noise signal, and carrying out the FrFT processing of the environment noise signal, and obtaining an environment spectrum vector; S2, obtaining a double-chaotic sequence through an improved Logistic mapping structure, processing the double-chaotic sequence, and obtaining a pseudo-random phase through FrFT; S3, after the environment spectrum vector is matched with the pseudo-random phase, carrying out amplitude adjustment to obtain an FrFT domain basis function, and carrying out IFrFT on the FrFT domain basis function to obtain a time domain basis function; S4, performing baseband mapping on the time domain basis function of the transmitting end at the transmitting end to obtain a spread spectrum signal, and sending the spread spectrum signal to a receiving end; and S5, performing related demodulation on the spread spectrum signal at a receiving end through a time domain conjugate basis function of thereceiving end to obtain an information signal. The method has better concealment, anti-interference capability, anti-multipath capability and the like, and can realize reliable communication under a very low signal-to-noise ratio.

Description

[0001] This application claims the priority of the Chinese patent application submitted to the China Patent Office on July 12, 2019, the application number is 201910631771.3, and the title of the invention is "A Transformation Domain Underwater Acoustic Communication Method Based on Chaotic Spread Spectrum", the entire content of which is passed References are incorporated in this application. technical field [0002] The invention relates to the field of underwater acoustic communication, in particular to a transformation domain underwater acoustic communication method based on chaotic spread spectrum. Background technique [0003] The underwater acoustic channel is complex and changeable. It is a very complex time-varying, frequency-varying, and space-varying channel. It is mainly manifested in: limited channel bandwidth, serious multi-channel distribution, fast and changeable channel fluctuations, and harsh environmental noise . Therefore, the propagation process of soun...

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Problems solved by technology

[0007] In view of the aforementioned problems of low concealment and low anti-interference in underwater acoustic communication, and poor reliability of underwater acoustic communication at low power, an embodiment of this application provides a transform domain underwater acoustic communication based on chaotic spread spectrum. method, including the following steps:

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