基于空时联合变采样波束形成的水声通信多普勒估计与补偿方法
Doppler estimation and compensation method for underwater acoustic communications based on time-space joint non-uniform sampling beamforming
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摘要: 针对正交多载波超宽带水声通信信号在低采样率条件下多普勒估计误差大, 补偿效果差的问题, 提出了一种结合阵列信号处理的水声通信多普勒估计与补偿方法。该方法利用阵列各阵元接收信号相位延迟特性, 借助时延标定法、双指针排序法及三次样条插值技术实现空时联合非均匀变采样方法, 完成波束域信号的快速高精度重建, 在保障获取阵列处理增益的同时, 提升了信号等效采样率, 从而实现了更高精度的多普勒估计和补偿。仿真结果表明, 与基于时域有限冲激响应滤波器波束形成的多普勒估计与补偿方法相比, 所提方法的多普勒估计均方根误差显著降低, 并且通信误码率得到有效改善。海试结果进一步验证了所提方法的有效性。Abstract: 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.