Based on the properties of DPSK (differential phase-shift keying) signal in Rayleigh flat-fading channels

we propose a novel decision aided algorithm for iterative DPSK signal demodulation/decoding.It utilizes decision feedback bits to estimate the channel coefficients and calculate the likelihood ratio of information bits.Compared with conventional iterative DPSK signal demodulation/decoding based on the BCJR (Bahl-Cocke-Jelinek-Raviv) algorithm

the new algorithm results in considerably low decoding cost yet can achieve nearly the same performance.