Multistage receiver for differential space-time block codes

Tarokh's differential space-time block codes (DSTBC) can provide full spatial diversity and can be decoded without channel state information. The bit error rate performance of a conventional differential detection has 3-dB degradation compared to a coherent detection in a quasi-static fading channel. Differential detection experiences more degradation in a fast fading channel and error floor appears at high SNR. In [5], an approximate maximum likelihood receiver was derived and it reduced the error floor significantly. In this paper, we modify the receiver in [5] and apply the concept of multistage decision-directed estimator with intrablock-interference cancellation to obtain further improvement. The proposed receiver works efficiently at moderate to high SNR and at the fading rate between f(d)T = 0.02 and f(d)T = 0.07.