Research And Implementation Of Underwater Acoustic Communication Technology Based On Chaotic Spread Spectrum

Underwater acoustic communication technology plays an important role in the Marine development.Anti-interference is an important indicator to measure underwater acoustic communication technology,due to water acoustic channel complex.A chaotic spread spectrum code division multiple access underwater acoustic communication method is proposed in this thesis,which effectively improves the anti-interference ability of underwater acoustic communication system.Fristly,three typical chaotic maps were introduced.For the problem that a single chaotic map sequence is easily intercepted and cracked,the cascaded method is used to generate a compound chaotic sequence,which improves the complexity of chaotic sequences.On this basis,the hop-and-line interleaving method is used to interleave chaotic sequences,which shortens the number of iterations of chaotic sequences entering chaotic state.According to the narrow channel available characteristics of the underwater acoustic channel,the chaotic phase modulation method is used to concentrate the spectrum of the chaotic sequence to the specified frequency band and maintaining the chaotic characteristics of the chaotic spreading sequence at the same time.Secondly,use good correlation properties of real-valued chaotic sequence,a number of chaotic sequence code channels are constructed.Based on this,combined with spread spectrum communication,chaotic spread-spectrum code division multiple access underwater acoustic communication technology is proposed.Then,aiming at the communication scheme of this paper,a hardware communication system and corresponding modulation and demodulation algorithm are designed.Finally,the feasibility of the communication scheme of this paper is verified by the pool experiment.On this basis,the anti-interference of the communication system was tested by adding interference sources.And the result proves that the communication algorithm designed in this paper effectively improves the anti-interference ability of spread spectrum communication.