非周期长码直扩信号PN码盲估计

针对低信噪比下非周期长码直扩信号PN(pseudo-noise)码盲估计问题,在已知码片速率和PN码周期前提下,提出一种基于特征值分解和梅西算法的非周期长码直扩信号PN码盲估计方法。在PN码周期内根据扩频调制比对信号,进行非重叠分段;利用分段矩阵特征值分解的方法估计各段PN码并进行拼接;通过滑动搜索窗,利用梅西算法得到PN码生成多项式,消除在拼接时产生的相位模糊。仿真结果表明,该方法适用性广,能够在较低信噪比下正确估计出m序列、Gold序列。

Blind estimation of PN codes for non-periodic long-code DSSS signals

Focusing on blind estimation of the PN codes for non-periodic long-code direct sequence spread spectrum(DSSS)signals under low signal-to-noise ratio(SNR),a blind estimation approach of PN codes was proposed based on eigenvalue decomposition and Massey algorithm on the premise of knowing chip rate of the PN code and the PN codes period.The received signal was divided into several non-overlapping segments according to the spread spectrum modulation ratio in the PN codes periods.Each segment of PN codes was estimated and spliced using the method of piecewise matrix eigenvalue decomposition.The Massey algorithm was used to obtain the PN code generator polynomial for eliminating the phase blur generated during the stitching by sliding the search window.The simulation results show that the proposed method is widely applicable and using it can correctly estimate the m-sequence and Gold-sequence in low SNR.