基于相位校正的时差估计算法研究

Research on TDOA Estimation Algorithm Based on Phase Correction

针对运动目标的时差测量问题,分析了主辅站之间的信号相位差随时间的变化规律,讨论了变化的相位差对相关峰值检测和时差测量精度的影响,给出了积分时间、多普勒频差和相关值衰减之间关系的理论曲线。在此基础上,提出了一种相位校正算法,克服了周期性变化的相位差对相关峰值的抑制效应。理论分析和仿真结果均表明,相位校正后时差估计精度显著提高,与无多普勒频差的情况非常接近。

Focusing on the problem of TDOA measurement of moving targets, this paper first analyses the change rule of phase difference between main station and slave one with time, and discusses the effects of varying phase difference on correlation peak detection and TDOA measurement precision,and presents theoretical relation curve among integration time,doppler frequency shift and correlation attenuation,then presents a new phase correction algorithm,which overcomes suppression effect of periodic phase difference on correlation peak. Both theoretical analysis and simulation results show that TDOA measurement precision has been increased significantly with phase correction, which approaches the case without Doppler.