Combined Doppler estimation method for underwater acoustic communication system

Abstract

The invention discloses a combined Doppler estimation method suitable for an underwater acoustic communication system. The method comprises the steps of S1, performing carrier capture and coarse synchronization by adding a start frame of an LFM+CW signal; and S2, performing fine synchronization by determining a peak value offset of an LFM signal. The step S1 includes the steps: after a first LFM signal is identified by an LFM pulse compression peak value obtained by the matched filtering, the single carrier is captured and coarsely synchronized by a COSTAS ring to obtain an initial Doppler estimation result, and the sampling rate is adjusted for the first time. Compared with the prior art, the method of the invention has the advantages of accurate and reliable estimation results, small calculation amount, simple realization, strong real-time performance, easy realization and so forth.

Description

technical field

[0001] The invention relates to the technical field of underwater acoustic communication, in particular to a combined Doppler estimation method suitable for an underwater acoustic communication system. Background technique

[0002] With the frequent development of oceans, the underwater acoustic communication system has great application value not only in the military field, but also in the civilian field. Such as marine water quality monitoring, marine disaster early warning, resource exploration, etc. The underwater acoustic communication system based on multiple-input multiple-output Orthogonal Frequency Division Multiplexing (OFDM) has become an important development direction in the field of underwater communication due to its advantages of high data transmission rate and high reliability. However, OFDM has relatively high requirements on frequency accuracy. When there is a frequency offset, the orthogonality of subcarriers is destroyed, which will caus...

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