Convergence of iterative decoding without channel estimation

Iterative decision-feedback (DFB) differential demodulation (DFDM) has recently been introduced for low-complexity noncoherent detection. The convergence analysis of this iterative decoding scheme is complicated since hard-decision decoding is involved. We develop an equivalent iterative decoder model which lends itself to a convergence study and as such constitutes a powerful tool for system design and analysis. Furthermore, we propose a modification of iterative DFDM which significantly improves convergence and hence power efficiency.