Doppler estimation and compensation method for underwater target active detection based on communication signal

基于通信信号的水下目标主动探测多普勒估计与补偿方法

School of Marine Science and Technology, Northwestern Polytechnical University, Xi’an 710072, China

Received: 25 December 2020

Abstract

The integration of underwater detection and communication uses communication signals to detect a target actively, but the Doppler effect deteriorates the parameter estimation performance of the integrated system. To eliminate the influence of the Doppler effect, a joint Doppler estimation and compensation method based on spectrum zooming and correction is proposed. Firstly, the synchronization signal is used to obtain the signal receiving delay and intercept the single-frequency signal segment in the received signal. Then, the discrete Fourier transform is used to find the frequency that corresponds to the maximum amplitude of the single-frequency signal segment. Finally, the frequency spectrum is refined and corrected within the range near the frequency. The Doppler factor is estimated and the received signal is compensated by the Doppler estimation value. The simulation results show that the proposed method improves Doppler factor estimation accuracy, increases the cross-correlation processing gain and improves DOA (direction of arrival) estimation performance, thus being robust to different Doppler effects.

摘要

水下探测通信一体化利用通信发射信号进行目标主动探测，而多普勒效应的存在使得主动探测中目标参数估计性能恶化。为了消除多普勒效应的影响，提出一种基于频谱细化与校正的联合多普勒估计和补偿方法。该方法利用通信发射信号中的同步头信号获取目标回波信号时延，截取信号中的单频信号段。再利用离散傅里叶变换（DFT）求得单频信号段最大幅值所对应的频率，并在该频率附近范围内进行频谱细化与校正求出频率偏移量，从而估计出多普勒因子，并根据所估计的多普勒因子对接收的目标回波信号进行补偿。仿真结果表明，所提的频谱细化与校正联合多普勒估计与补偿方法提高了多普勒估计精度，使多普勒补偿后的信号与发射副本相关处理增益增加，提高了波达方向（DOA）估计性能，并且对不同多普勒效应具有良好的鲁棒性。