Based on the method of subspace, the problems of the estimation of active users and timing in asynchronous CDMA systems are studied, the algorithms of the estimation of active user and timing are given, and the performances are analyzed.

• 本文利用子空间方法将接收信号的自相关矩阵分解为信号子空间和噪声子空间，并根11 多子汲分折及其在mMA中的应用据信号子空间与噪声子空间的正交性估计出期望用户的广义特征向量，进而求解出期望用户的信道参数及时延。 这种方法的特点是算法简单、可进行动态估计并且不需要训练序列。