基于脉冲重复间隔变换的脉冲重复间隔估计

Estimation of pulse repetition intervals based on PRI transform

传统的脉冲重复间隔估计方法是以计算接收到的脉冲串的自相关函数为基础 ,很容易出现信号的脉冲重复间隔及其整数倍 (即子谐波 )同时存在的现象 ,给雷达脉冲去交叉造成了困难 .为克服上述缺点 ,提出了基于脉冲重复间隔变换的脉冲重复间隔估计方法 ,几乎完全地抑制了出现在自相关函数中的子谐波 .研究了这种算法对于稳定重频、参差重频、抖动重频、滑变重频的适用性 .计算机仿真结果表明 ,这种算法在检测各种信号的脉冲重复间隔时 ,具有较强的适用性 .此外 ,对于重频抖动的信号 ,为了获得良好的检测效果 ,需要改变容差参数的大小 ,因此也讨论了改变容差参数的方法 .

The pulse repetition interval (PRI) is one of the important parameters of signal sorting. The traditional algorithms for estimating PRI are based on the autocorrelation function of the pulse train. The autocorrelation function peaks are yielded not only at the locations of PRI contained in the original pulse train but also at the locations of the integer multiple of the fundamental PRI, i.e., 'subharmonics' which make it difficult to deinterleave pulse trains. In order to overcome the drawback, the algorithm for estimating pulse repetition intervals based on the PRI transform is introduced in this paper, which can suppress the subharmonics in the autocorrelation function almost completely. Emphasis is put on discussing the capability of the algorithm to deinterleave various radar signals with varied PRI. Research results based on computer simulation show that this algorithm is capable of detecting the PRI of various signals. In order to get better detecting results, it is necessary to vary the tolerance parameter in the PRI transform. The technique for selecting the tolerance parameter is also discussed.