一种DS-CDMA系统扩频码和参数盲估计方法

New Method for Blind Estimation of PN Code and Parameter in DS-CDMA System

传统DS-CDMA系统扩频码盲估计方法以主元分析为基础,若各用户扩频码非正交(即存在多址干扰)则将导致扩频码估计失效。本文通过码域映射、信息码盲分离以及相应的信号处理手段,实现了多用户情况下的扩频码、延时信息以及信息码的盲估计。该方法无需已知任何同步信息,允许系统存在较差的信噪比和多址干扰。仿真实验表明,对异步DS-CDMA系统该方法有效可行。

Most of the traditional methods of blind PN code estimation in DS-CDMA are based on principal component analysis （PCA）. Those methods will be disabled when the PN codes of the users are non-orthogonal which means the existence of multiple access interference （MAI） in the system. A new method is proposed to solve the influence of MAr ignored in traditional PN code estimation. The blind estimations of PN code, time delay and information code in DS signal are realized by code space projection, blind signal separation and some other signal processing technology. The method can work in low SNR and hard MAI conditions without the supplied synchronous information. Simulations show that the new method is efficient in asynchronous DS-CDMA system.