Iterative decision-feedback differential demodulation of bit-interleaved coded MDPSK for flat Rayleigh fading channels

A simple receiver structure recently proposed by the authors for convolutio nal coded M-ary differential phase-shift keying transmission over flat Rayl eigh fading channels without channel state information is analyzed in detai l. We present a thorough discussion of the iterative decoding procedure, wh ich is referred to as iterative decision-feedback differential demodulation (iterative DF-DM), The convergence behavior of iterative DF-DM is theoreti cally examined. The analysis supports the observation that the iterative de coding scheme works well for target bit-error rates which are usually of in terest. Furthermore, the associated cut-off rate for error-free decision fe edback is studied. Judging from this performance parameter, remarkable gain s in power efficiency compared to conventional differential demodulation ar e indicated, while the computational complexity of the decoding remains low . The results from information theory are in good agreement with the given simulation results.