基于最优格拉斯曼序列的多用户检测

摘要

CDMA系统中，一般要求扩频码本具有较低的互相关性。最优格拉斯曼序列是序列间互相关达到最低的码本，且任意两个序列具有相同的互相关。因此，最优格拉斯曼序列具有较稳定的码本结构。但当激活用户数较多时，采用单纯的多用户检测技术仍具有较高的误码率。提出了一种基于最优格拉斯曼序列的多用户检测预处理方法，在对接收信号进行多用户检测前，提取出能够被最优判决的用户信号，使误码率和多用户检测的计算复杂度均得到降低。%In CDMA system, the cross-correlation of spreading spectrum codebook is generally required to be relatively low. The optimal Grassmannian sequence, the lowest cross-correlation codebook in se-quences, enjoys identical cross-correlations between every two sequences. Thus, the codebook structure of optimal Grassmannian sequence is fairly stable. However, when the number of active users is large, the error rate is still high by adopting simple multi-user detection technology. A preprocessing method for multi-user detection based on optimal Grassmannian sequence is proposed, and this method is applied to extract optimally-decided users signal before multi-user detection on received signal, thus to decrease both the error rate and the computation complexity of multi-user detection.