Performance of space-time block coded system over frequency selective fading channel using semi-blind channel estimation technique

To achieve high system capacity over frequency-selective fading channel, multi-carrier code-division-multiple-access (MC-CDMA) system with spatial diversity using space-time block coding (STBC) is considered. We present a subspace-based semi-blind channel estimation method under multiuser environment to resolve the inherent scalar ambiguity when blind estimation technique is used. Mean-square-error (MSE) expression for the proposed channel estimation technique is derived. Bit-error-rate (BER) when using linear zero-forcing (ZF) and minimum-mean-square-error (MMSE) multiuser detection techniques taking the channel estimation error into consideration are obtained through simulation. The correctness of the BERs is further verified through estimating the signal-to-interference and noise-ratio (SINR) at the multiuser detectors.