线性调频信号的时延估计方法

Time Delay Estimation for Chirp Signal

无源时差定位是一种重要的无源定位方法,具有精度高、定位快等特点,在工程中得到了广泛的应用。但是,时差定位系统的精度主要取决于时延估计的精度,研究快速准确的时延估计方法成为时差定位系统中一个重要的课题。该文选取雷达信号中常用的线性调频信号为研究对象,根据线性调频信号具有的循环平稳特性,讨论了循环互相关时延估计方法在该信号上的应用。利用循环互相关时延估计方法在较低的信嗓比条件下能准确地得到时延值,能有效地抑制噪声。通过计算机仿真试验,证明该方法比传统的广义互相关方法具有更强的抗噪性能。

Time difference of arrival is an important passive location method which been widely used in practice.But its precision depends on time delay estimation.In this paper,the cyclostationary characteristic of chirp signal is studied and the time delay estimation method is carried out based on the correlated cyclic cross-correlation. The time delay is precisely estimated due to noise suppression of the method.Computer simulations results shows that the performance of the new method is better in noisy circumstance than the conventional generalized cross-correlation method.