Space-time MMSE multiuser receiver for space-time coded DS/CDMA systems in frequency selective fading channels

We present a space-time MMSE multiuser detector for diversity combining and interference suppression. We employ and extend the basic structure of [Matti Latva-aho et al., Feb. 2000], which uses the multiple MMSE filter, to combine the space time decoding and multiuser detection with simultaneously suppressing MUI and achieving the diversity gain at both space and time. To decode the space-time code with the space diversity gain, we stack the received signal during two space-time-coded symbol intervals and conjugate the second symbol interval as in [Hong bin Li et al., May 2002]. We also combine the multipath signals with the equal gain or proportional gain to the power of propagation path to obtain the time diversity. We present numerical results to chow the performance of the proposed receiver.