Improvement and analysis of iterative decision-feedback differential demodulation

In this letter, we consider iterative decision-feedback differential demodulation (iterative DFDM), which was proposed previously as a low-complexity solution for power-efficient transmission over flat fading channels without channel state information at the receiver. We devise a modified demodulator (inner decoder), which improves both the achievable bit-error rate performance and the convergence of iterative DFDM without increasing complexity. We also establish an equivalent decoder model for iterative DFDM which enables a convergence analysis by means of extrinsic information transfer charts.