Underwater mobile spread spectrum communication method based on frequency compression-energy receiver

Abstract

The invention discloses an underwater mobile spread spectrum communication method based on a frequency compression-energy receiver, and particularly relates to the field of communication, and the method comprises the following steps: S1, a communication transmitting end sets a two-dimensional combined differential spread spectrum frame structure to carry out index modulation and polarity modulation respectively; s2, Doppler coarse estimation is completed through a repetition code correlation peak time domain difference; s3, the communication receiving end performs spread spectrum index decoding by using a frequency compression-energy receiver; and S4, the communication receiving end carries out combined differential polarity decoding. Compared with the traditional phase-locked loop technology, the method for coping with the phase jump in the underwater sound robust spread spectrum communication is suitable for complex sea conditions with low signal-to-noise ratio; through test data analysis under the background of complex relative motion and low signal-to-noise ratio, the method is low in error rate.

Description

technical field [0001] The present invention relates to the technical field of underwater acoustic communication, and more particularly, to an underwater mobile spread spectrum communication method based on a frequency compression-energy receiver. Background technique [0002] Although the direct sequence spread spectrum communication technology can obtain higher spread spectrum gain, it is more sensitive to the phase hopping caused by the Doppler effect of the underwater acoustic channel and has a low communication rate. There are certain challenges when communicating reliably. [0003] In terms of anti-carrier phase hopping to achieve robust underwater spread spectrum communication, the traditional method is to use phase-locked loop technology to dynamically track the change of carrier frequency and phase after the acquisition and locking are completed. In recent years, the research on robust spread spectrum communication has mostly focused on the time-domain differential...

AI Technical Summary

Problems solved by technology

Aiming at the problems of phase jump and sharp drop in spread spectrum gain in traditional spread spectrum communication in underwater mobile communication, the present invention designs a 2-dimensional combined differential symbol frame structure and utilizes repetition code related time domain deviations to carry out relative motion Doppler On this basis, a frequency compression-energy receiver is proposed to improve the Doppler tolerance of the receiving end to meet the requirements of greater relative velocity, greater relative acceleration, greater relative acceleration change rate and low signal-to-noise Underwater Mobile Spread Spectrum Communication under Specific Conditions

Images