基于延时相乘及其改进算法的DS/FH信号率线检测

针对DS/FH（直扩/跳频）混合扩频信号截获和参数估计问题，提出了一种基于延时相 乘结合自适应滤波和分段自相关的新方法。该算法首先将输入信号进行自适应滤波以提高 信噪比，滤波后送入延时相乘器，最后将乘积后数据分段进行自相关，通过分析谱图即可检 测DS/FH混合扩频信号的码速率谱线。计算机仿真显示，改进的算法不但能适应低信噪比( -2 0 dB)条件下DS/FH混合扩频信号的检测，而且同时能够实现对码速率的估计。该方法所用 算法简单，适合采用硬件设计实现，且如果是合作目标信号，搜索时间短，实时性强。

Detection and chip rate estimation of DS/FH hybrid signals based on delay-multiply and its improved algorithm

To deal with the issue of DS/FH(direct sequence spread spectrum /frequency hopping) hybrid signal interception and parameter estimation,a novel algorithm based on delay-multiply,sectional auto-correlation and adaptive filter is proposed.In this algorithm,the input signal is processed by adaptive filter to improve signal-to-noise ratio(SNR) first.Secondly,the filtered signal is sent to delay-multiply and sectional auto-correlation is performed.Finally,the chip rate can be detected by analysing the power spectrum.The computer simulations show that it can not only fit the need of the low SNR(about-20 dB) which is quite common in the detection of DS/FH signals,but also can give the estimations of the chip rate in a simple way.This algorithm has little calculating demand so it is suitable for hardware implementation.If the input signal is cooperative signal,the search time will be shorter,and the algorithm has good capability in real-time processing.