Parallel multistage equalizer with partial decision feedback for layered space-time frequency-selective channels

Space-time transmission techniques, which make full use of the rich scattering channel with multiple transmit and receive antennas, can greatly increase the spectral efficiency. In this paper, a novel parallel multistage equalizer with partial decision feedback (PDF) is proposed for the layered space-time frequency-selective channel. It is comprised of a partial parallel interference canceller, a MIMO decision feedback equalizer and a linear combiner. Performance analysis shows that the proposed receiver is equivalent to the partial parallel interference cancellation (PPIC) using MMSE for initial estimation and tentative decisions. By using past- and post-symbol estimation to regenerate intersymbol and co-antenna interference, the proposed receiver can be further improved with partial decision feedback. Moreover, the proposed equalization schemes could be implemented by negligible complexity increase comparing with the other well-known approaches. Simulation results show that the proposed equalizers with PDF significantly outperform the conventional MIMO decision feedback equalizer without interference cancellation (IC) and MIMO equalizer with ordering successive interference cancellation (OSIC).