一种新的基于多用户去相关的波达方向估计方法

以直接序列码分多址 (DS/CDMA)系统中的天线阵为背景 ,讨论了一种新的基于多用户去相关的波达方向 (DOA)估计方法 .该方法在基站对各用户波达时延估计的基础上 ,根据扩频序列表现出的周期性和非完全正交的性质 ,通过充分利用多址干扰部分表现出的信息 ,自相关处理后再去相关 ,进而同时实现对各用户的DOA、信号功率与噪声功率的精确估计 .该方法不是简单地将多址干扰部分当作噪声进行处理 ,而是通过去相关的方法来消除它们的影响 ,因此 ,该方法不仅在低信噪比下具有高估计精度 ,对系统中存在的远近效应的影响也有一定的抵抗能力 .仿真实验验证了该方法的有效性 .

A New Direction of Arrival Estimation Algorithm Based on Multiuser Decorrelator

This article proposes a new direction of arrival (DOA) estimation algorithm based on multiuser decorrelator with an antenna array used in the base station of direct sequence code division multiple access (DS/CDMA) system. By exploiting the information exhibited by multiple access interferences for the periodicity and non orthogonality of spreading sequences, the algorithm performs autocorrelation processing first, decorrelates and then estimates DOAs and signal powers of all users and noise power simultaneously under the assumption of knowing the time delays. The algorithm does not treat simply the multiple access interferences as noise, but utilizes decorrelation to eliminate their effects. The algorithm therefore has higher estimation precision even in lower signal to noise ratio (SNR). It also has some resistance to near far effect. The simulation demonstrates the effectiveness of the proposed algorithm.