【摘要】 讨论了异步直接序列码分多址 (DS CDMA)系统中多用户环境下的波达方向 (DOA)估计问题 ,针对路径总数大于天线阵元数这一问题 ,提出了一种有效的DOA估计模式 .通过抵消干扰信号的相关阵 ,可方便地提取出感兴趣信息 ;此时 ,采用传统的DOA估计算法即可逐次估计出各DOA信息 .为改善系统性能 ,本文提出了 2种改进措施 :Mahalanobis变换法及矩阵点除算法 .前者能够大幅度地提高估计精度 ,而后者则可避免特征值分解运算 ,大大降低算法复杂度 .仿真实验验证了算法的有效性 .更多还原

【Abstract】 The DOA (direction of arrival) estimation for asynchronous DS-CDMA (direct sequence code division multiple access) systems in multi-user environments is discussed. An effective DOA estimation pattern is presented for the situation that the number of all the paths exceeds that of antenna array’s elements. Based on the counteraction of the correlation matrices of interferences,signals of interest (SOI) are conveniently extracted. In the meantime,DOA’s of each path can be resolved serially from the SOI using the conventional DOA estimation algorithms. Furthermore,two scenarios - Mahalanobis transform and element-wise division algorithm,which improve the system performances,are provided. The former improves the estimation accuracy and the latter decreases the complexity as eigenvalue decomposition can be avoided. Simulation results confirm the effectiveness of the algorithm.更多还原