Passive time reversal underwater sound communication method suitable for mobile platform

Abstract

The invention discloses a passive time reversal underwater sound communication method suitable for a mobile platform, wherein at least a receiver or a sender moves, the same information frame is repeatedly emitted on different position points, and channel transfer functions on different position points have lower correlation. A receiving end carries out pretreatment, such as frame synchronization, time reversal convolution, Doppler correction and the like, to a received signal, then merges a plurality of pretreated signals received on different opposite positions, and recovers emission information by operations, such as symbol synchronization, spread spectrum sequence correlation and the like. The invention has the beneficial effects that level correlation of a underwater sound communication channel is weakened by using position changes to provide a space diversity effect for time reversal treatment; the configuration of the time reversal communication system is lowered, and for the minimum configuration, the receiving end and the sending end are needed to be provided with only one real object array element respectively. Meanwhile, the same information frame is repeatedly emitted at different time points to obtain the time diversity effect, thereby obviously improving the reliability of the underwater sound communication system in the complex environment.

Description

technical field [0001] The invention relates to the field of underwater acoustic communication, and mainly relates to a passive time-reverse underwater acoustic communication method suitable for a mobile platform. Background technique [0002] In the underwater acoustic channel, due to the influence of the interface (bottom, sea surface) reflection, the channel multi-channel extension is very serious, especially in shallow seas, the multi-channel extension may sometimes reach hundreds of milliseconds, and the inter-symbol interference generated by the multi-channel extension is underwater. One of the major obstacles to acoustic communication. [0003] Time reversal (referred to as time inversion) processing technology is an effective means developed in recent years to overcome inter-symbol interference caused by multi-path in underwater acoustic communication. According to the difference of hardware configuration and data flow direction, time reversal technology can be divi...

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Problems solved by technology

[0009] Literature 1 and Literature 2 study the passive time inverse spread spectrum communication method based on a single hydrophone. Invention 1 proposes an underwater space division multiple access scheme based on a single hydrophone’s passive time inverse processing. However, the theory and experiments have proved that in Under complex underwater acoustic multi-channel channels, only a single hydrophone is used for passive time inverse processing, the communication quality is greatly affected by the channel environment, and it is often difficult to obtain stable low error bit performance

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