基于倒序相关累加的信号到达时间盲估计

Blind Arrival Time Estimation of Signals Based on Correlation and Reversed Accumulation

研究了在信号频率、初相、幅度未知条件下,矩形包络复正弦信号到达时间盲估计算法。先利用相关检测,对信号的起、止时间进行粗估计,估计出信号频率,并将其变换到基带,经倒序累加后的信号模值,在到达时刻将出现拐点并达到最大输出信噪比,检测出拐点位置,作为到达时间精估计。文中推导了离散矩形包络复正弦信号到达时间估计的克拉美罗限。计算机仿真表明,本方法在较低信噪比条件下可实现对信号到达时间的精确估计。

The problem of estimating time of arrival （ToA）of complex sinusoid with rectangular envelope is considered. In the absence of a prior knowledge for the signal parameters （amplitude, phase and frequency）, Firstly the coarse estimation of the start position and the end position by the correlation detection is performed, Then, the received signal is transformed to baseband one with the frequency estimation. The start position of the signal can be effectively extracted by locating accumulation inflection point of the reversed baseband signal with the maximum output signal noise ratio （SNR）. The Cramer-Rao lower bounds （CRLB） for ToA estimation is derived. Simulation results show that the proposed method can accurately estimate ToA under the condition of lower SNR.