Mobile underwater acoustic communication method

Abstract

The invention provides a mobile underwater acoustic communication method which includes the following steps: carrying out channel encoding and digital modulation on a data source at a sending end to get serial data, and converting the serial data into a parallel data flow; inserting pilot data into each group of parallel data, and carrying out sub-carrier modulation through inverse fractional Fourier transformation; adding a guard interval to modulated symbols, converting the modulated symbols into serial data, and sending the serial data; carrying out serial-to-parallel conversion and removing the guard interval at a receiving end, and searching for the optimal order through an order scanning search iterative algorithm; carrying out sub-carrier modulation on signals through optimal-orderfractional Fourier transformation, and carrying out channel estimation and equalization in the fractional Fourier domain at the receiving end; and after equalization, removing the pilot data, carryingout parallel-to-serial conversion to get serial data, carrying out digital demodulation and channel decoding, and outputting obtained data from the receiving end. The method has the advantages of simple structure and high calculation speed. The algorithm complexity of the transmitter and the receiver is reduced. The Doppler frequency shift in underwater acoustic mobile communication is reduced. The communication effect is improved.

Description

technical field [0001] The invention relates to the field of underwater acoustic communication, more specifically, relates to a method for realizing underwater acoustic mobile communication. Background technique [0002] There is a huge gap between the development of underwater acoustic communication technology and the development of terrestrial radio communication. The main reason is that the underwater acoustic channel is a time-varying, space-varying and frequency-varying channel, and its transmission characteristics are complex and changeable. [0003] Orthogonal frequency division multiplexing multi-carrier modulation technology (OFDM) has the advantages of high rate, high spectrum utilization, anti-multipath effect, etc., but at the same time, OFDM technology also has some disadvantages: it is very sensitive to frequency offset and phase noise, frequency offset The shift and phase noise will destroy the orthogonality between the subcarriers; when there is relative moti...

AI Technical Summary

Problems solved by technology

[0003] Orthogonal frequency division multiplexing multi-carrier modulation technology (OFDM) has the advantages of high rate, high spectrum utilization, anti-multipath effect, etc., but at the same time, OFDM technology also has some disadvantages: it is very sensitive to frequency offset and phase noise, frequency offset shift and phase noise will destroy the orthogonality between subcarriers; when there is relative motion at the two ends of the transceiver, the Doppler frequency shift in the system is obvious

In addition, the OFDM communication method based on fractional Fourier transform has so far been rarely studied in the field of underwater acoustic mobile communication.

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