Doppler estimation and compensation method for underwater acoustic communications based on time-space joint non-uniform sampling beamforming

To address the problem of large Doppler estimation error and poor compensation effect of orthogonal multi-carrier ultra-wideband underwater acoustic communication signals under low sampling rate conditions, this paper proposes a Doppler estimation and compensation method for underwater acoustic communication based on array signal processing. By utilizing the phase delay characteristics of the signals received by the array elements, the proposed space-time joint non-uniform sampling method is realized through time delay calibration, double-pointer sorting algorithm, and cubic spline interpolation technique, which achieves fast and high-precision reconstruction of the beamformed signal. While ensuring the acquisition of the array processing gain, the sampling rate of the signal is improved, thereby realizing higher-precision Doppler estimation and compensation. Simulation results show that compared with the Doppler recognition method based on time-domain finite impulse response filter beamforming, the proposed method significantly reduces the root mean square error of Doppler estimation, and effectively improves the communication bit error rate. Experimental results further validate the effectiveness of the proposed method.