Underwater sound time-varying channel measurement and single carrier frequency domain equalization method based on frequency division pilot frequency

Abstract

The invention discloses an underwater acoustic time-varying channel measurement and single carrier frequency domain equalization method based on frequency division pilot frequency, and belongs to the technical field of underwater acoustic communication and positioning. According to the invention, the problem of poor frequency domain equalization performance caused by inaccurate Doppler compensation of the existing method is solved. According to the method, the pilot frequencies are inserted at different frequency positions, so that the receiving end can realize refined estimation and compensation of the Doppler factor by utilizing the correlation between the pilot frequencies. And a receiving end performs Doppler parameter extraction on a pilot signal based on amplitude-phase joint estimation of complex autocorrelation, so that high-precision Doppler factor estimation and correlation peak time delay information are obtained, and effective compensation for a time-varying Doppler channel is realized. According to the method, complex fuzzy function search is not needed, and the system complexity is remarkably reduced. And meanwhile, the time-varying channel is continuously tracked through the pilot frequency band of frequency division, so that the robustness and the communication reliability of frequency domain equalization under the time-varying channel are effectively improved. The method can be applied to underwater sound time-varying channel measurement and frequency domain equalization.

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