On the robustness of decision-feedback detection of DPSK and differential unitary space-time modulation in Rayleigh-fading channels

Decision-feedback differential detection (DFDD) of differential phase-shift keying (DPSK) and differential unitary space-time modulation (DUST) in Rayleigh fading channels exhibits significant performance improvement over standard single-symbol ML detector, but it requires the knowledge of fading correlation and SNR at the receiver. In this paper, we investigate the robustness of the DFDD to imperfect knowledge of fading correlation and SNR. We derive the exact and Chernoff bound expressions for pair-wise word-error probability (PWEP), and then use them to approximate the BER, finding close agreement with simulation results. The relationships between performance and various system parameters, e.g., DFDD length and Doppler mismatch are also explored.