基于Haar小波变换的直扩信号伪码盲同步方法

为了解决非合作条件下短码直接序列扩频信号的盲同步问题,提出了一种基于Haar小波变换的伪码同步方法。该方法不需要事先知道扩频序列,先将直扩信号进行延迟相乘和低通滤波处理,计算其Haar小波变换,再按照伪码周期分段进行累加,搜索幅度累计平均的峰值,即可估计出直扩信号的伪码同步时间。理论分析和仿真实验表明在低信噪比下,该方法仍具有较好的性能,而且计算量较小、数值稳定性好,易于工程实现。

Blind PN Synchronization of Direct Sequence Spread Signal Based on Haar Wavelet Transform

To realize blind pseudo-noise （PN） synchronization of short-code Direct Sequence Spread Spectrum signal in non-cooperative communication,an approach based on the Haar wavelet transform（HWT） is proposed,which requires no prior knowledge of the associated spreading codes. In this method,the DSSS signal is passed through a delay-multiply-filter,the HWT of the filter is computed and divided into M groups according to the period of PN sequence. Finally,the PN code synchronization could be achieved by searching the peak value of the accumulation results. Both theoretical analysis and numerical simulation show that the proposed method is efficient even at low signal-to-noise ratio. Furthermore, its computational complexity is much lower than that of other methods.