欠采样带通信号时延估计算法

Time Delay Estimation for Sub-Sampling Bandpass Signals

本文研究了带通信号的时延估计问题。由于带通信号载波的高频振荡,已有的时延估计算法在欠采样条件下无法得到精确的估计结果,尤其当延时真值不是采样间隔整数倍时,将出现无法克服的误差平台。本文通过分析,对这一问题给出了合理的解释,并提出了一种欠采样条件下的带通信号时延估计新算法。新算法利用相关函数的复包络估计时延很好地解决了上述问题,进而利用带通信号的特点提高了算法对噪声的鲁棒性。仿真结果说明,新算法的性能优于已有的时延估计算法。

Time delay estimation for bandpass signals is discussed in this paper. Due to the highly oscillatory carrier of bandpass signals, existing algorithms cannot achieve precise estimation under sub - sampling. Especially when the true delay is not integral multiple of the sampling interval, an irreducible error floor may be introduced. A reasonable explanation for this problem is given here. This paper also proposes a new time delay estimation algorithm for bandpass signals. Estimating time delay through complex envelope of correlation function, the new algorithm effectively resolves the above problem. Moreover, the new method is robust to noise by exploring the characteristics of bandpass signals . The simulation results demonstrate that the proposed algorithm is superior to those existing methods.