一种改进的时域平均法检测微弱信号研究

提出了一种变截断周期时域平均搜索方法，通过改变时域平均截断周期来搜索某一有限频带内的微弱周期信号。仿真表明，它的信噪比下限达到-35dB。

A Modified Time Averaging Method in Weak Signal Detection

This paper deals with a modified time averaging method for the detection of weak periodical signal. When the struncating period deviates the integral times of the signal period, the processing gain of time averaging deteriorates rapidly. However, noise added on the signal is attenuated at the same time. Our analysis indicates that noise attenuates faster than the signal does before the averaging times reach a threshold. If we manage to obtain the optimal averaging times, we can still get fairly high processing gain. Based on the above analysis, we propose a method to search weak periodical signal in a limited frequency band by changing the struncating period. Simulation shows that this method can detect weak periodical signal under a very low SNR of -35dB.