Abstract: A blind adaptive multiuser detector based on a modified constrained Kalman filtering algorithm in multipath Code-Division Multiple-Access（CDMA） communication channels was proposed.In order to facilitate the application of a blind linear filter-optimization technique to robust inference suppression，a new canonical representation for Kalman filter was developed first，and then an efficient iterative implementation that provided very fast convergence under this representation was presented.The proposed detector was significantly superior to the present least mean squares filter in convergence rate and bit-error-rate，and also it had a better tracking capability under the dynamic environment.Computer simulation results confirm that the proposed detector is effective in multipath fading channels.

Key words: blind multiuser detection, DS-CDMA, adaptive Kalman filtering, multipath fading channels

摘要： 基于盲检测器的新典范表示形式，提出了一种多径信道下CDMA系统的盲多用户检测器。该检测器使用了一种改进的自适应卡尔曼滤波算法，它在进行状态滤波的同时，在线估计时变的未知噪声统计特性，提高了算法的滤波精度，确保了算法收敛于期望用户。仿真表明，对比原有的随机梯度（LMS）算法，该算法的收敛、跟踪性能更好，且误码率减小了18.7%。

关键词: 盲多用户检测, 直扩码分多址系统, 自适应卡尔曼滤波, 多径衰落信道