Nonblind and semiblind space-time-frequency multiuser detection for space-time block-coded MC-CDMA

In this paper, a novel space-time-frequency minimum mean squared error (STF-MMSE)-based parallel interference cancellation receiver is proposed for space-time block-coded multicarrier code division multiple access systems in time-varying fading channels. The signal processing of this new detector is jointly implemented in space, time, and frequency domains, which leads to a powerful capability of combating interference coming from different sources. An adaptive implementation based on subspace estimation is proposed for slow-varying fading channels. Furthermore, based on the characteristic function of a complex Gaussian random vector, an analytical method to calculate the bit error probability of the proposed STF-MMSE receiver is presented. Representative examples of the detector are provided to demonstrate its superior performance.