Performance analysis of linear MMSE multi-user detection scheme for STTC-OTD WCDMA downlink

Space time trellis coded-orthogonal transmit diversity (STTC-OTD) scheme was proposed in S. Thirukkmaran and K.K. Pang (2004) and S. Thirukkmaran and K.K. Pang (2005) and its performance when applied to a CDMA system using a single user detector (SUD) was analyzed. It was therein shown that significant performance gain could be achieved using this scheme. Although this scheme requires extra spreading codes, the performance gains could more than offset the loss in cell capacity. In this paper our contribution is to analyze the performance of STTC-OTD scheme with a linear minimum mean squared error multiuser detection (LMMSE-MUD) receiver. We also provide, for comparison, the performance of the standard STTC scheme with a LMMSE-MUD receiver. It is shown that the performance of the STTC-OTD scheme with LMMSE-MUD receiver outperforms both STTC-OTD scheme with single user detection and STTC scheme with LMMSE-MUD.