摘要
与最大似然检测算法相比，解相关算法具有线性运算复杂度和不需要估计信道特征的优点。传统的逆矩阵滤波器在移动环境下不易实现，而滑动窗口算法对系统的定时有较严格的要求。基于信息码元之间的相关性随着时间间隔的加大而逐渐减小这个事实，本文提出了多用户异步DS／CDMA系统一种新的解相关算法─—延迟截断解相关算法：要判决当前时刻的信息码元，只需在延迟等待一定数量的码元之后截断，对截断后的码元按照传统的方法判决，这样就把异步系统等效为同步系统。模拟结果表明，当延迟的码元数和全部用户路径数基本相同时，传统判决的误差对算法性能的影响很小。算法适用于移动时变信道，并且对系统定时没有任何要求。
Based on the facts that the mutual influence between two information symbols of different users is reducing with the increasing of the time separation between these two symbols,we proposed the Delayed-and-Truncated Decorrelator(DTD)for the first time.According to the algorithm,the asynchronous system is simplified to a synchronous one by delay and truncation operation,however,the truncation error has little influence on the whole system performance. Compared with the present decorrelator algorithms,the DTD algorithm has the same precision and computational complexity but less processing delay.More important,this algorithm renders no special request to the system timing and synchronization.
出处
《通信学报》
EI
CSCD
北大核心
1999年第1期8-16,共9页
Journal on Communications
基金
国家自然科学基金
