WCDMA系统中的差分最小均方误差多用户检测算法研究

针对现有自适应多用户检测算法需要训练比特、不能适应快衰落信道的问题，提出适用于WCDMA系统的基于差分最小均方误差（DMMSE）准则的自适应多用户检测算法。该算法结合二级扩频体制的特点，根据具有相同综合扩频码的相邻接收符号幅度变化的比率变化自适应调整横向滤波器的权系数，由于该方法更能刻画多址干扰的变化规律，因此可有效地抑制多址干扰。仿真结果表明，在多普勒频移的传播环境下，DMMSE算法的误码性能优于现有自适应MMSE算法。

The study of multiuser detection algorithm based on the differential minimum mean square error criterion in WCDMA system

As existing adaptive algorithms need training bits and are unsuited to fast fading channel in WCDMA systems, a novel adaptive multiuser algorithm based on differential MMSE (DMMSE) criterion is presented in this paper. According to the typical characteristic of two-layered spreading modulation in the WCDMA systems, the proposed DMMSE criterion updates the weight coeffients of transversal filter by tracking the ratio of successive symbols with the same comprehansive spread sequence. Thanks to depict the multiple access interference (MAI) more properly, the proposed algritnm can suppress the MAI more effectively. Simulation results illustrate that proposed one performs better than the existed ones at the Doppler shift channel.