A method for mobile underwater acoustic communication

Abstract

The invention provides a mobile underwater acoustic communication method, which generates a DPLFM signal required for communication, modulates data to be transmitted, receives the signal through a mobile underwater acoustic communication channel at a receiving end, performs virtual time reversal processing, and finally filters and demodulates the received signal after the virtual time reversal. The invention uses PLFM signal to replace LFM signal as carrier signal of underwater acoustic communication system, and combines piecewise linear frequency modulation and FDM technology, so that spectrum utilization ratio and data rate of traditional LFM underwater acoustic communication method are effectively improved. At that same time, when the relative motion speed of the communication transmitend and the receiving end is low, the invention doe not need Doppler frequency shift compensation, and the performance of the OFDM underwater acoustic communication system compensated by the Doppler frequency shift can be consistent with or even better, and the invention has the advantage of simple algorithm.

Description

technical field [0001] The invention relates to the field of mobile underwater acoustic communication, in particular to related demodulation, segmented linear frequency modulation and other technologies, and is a relatively efficient mobile underwater acoustic multi-carrier communication method with low Doppler frequency shift and signal-to-noise ratio. Background technique [0002] Due to the existence of factors such as ocean currents and wind waves, there is often a certain relative speed between the transceivers in underwater acoustic communication. Therefore, the difference in propagation distance caused by movement causes the frequency and phase of the signal to change during transmission (ie Doppler frequency shift), and different from wireless communication, underwater acoustic communication often exists in wideband Doppler In addition to the frequency offset and phase shift, the signal also has the phenomenon of signal broadening or reduction. Therefore, the signal ...

AI Technical Summary

Problems solved by technology

However, due to the strong cross-correlation of LFM signals, the spectrum reuse rate of this method is low, and the bit error rate is relatively high when the system communication frequency band is relatively limited. The new signal whose cross-correlation is better than LFM can combine the idea of ​​frequency division multiplexing (FDM) to increase the data rate of LFM system in a limited frequency band

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