含同步误差的正交码CDMA系统性能分析

Performance of the orthogonal code CDMA system with synchronization errors

IS 95与WCDMA等正交码CDMA系统中均采用了相关接收机 ,所以只有在码元完全同步时才具有最优性能 ,但在实际接收机中 ,由于同步误差的存在 ,会导致系统性能的下降 .为此 ,文中着重分析了多径衰落信道中 ,存在同步误差与多址干扰时的正交码CDMA系统性能 ,推导了平均误比特率的计算公式 ,并在此基础上综合分析了信道特征、系统用户数、同步误差以及接收策略对系统性能的影响 ,为接收机的优化设计提供了理论依据和参考数据 .

The performance of the orthogonal code CDMA System in the Rayleigh fading channel is studied and the error probability expression is derived. Different from other documents, this paper focuses on the case of nonideal receiving conditions, which takes into account the effect of chip timing error and the multiple access interference (MAI). The RAKE receiver with the equal gain diversity combining scheme is also considered. Finally, the effects of channel characteristics, diversity schemes, synchronization errors and user numbers on the performance are discussed.