A Comparison of Soft-Decision Decoding Algorithms for Differential Pulse-Position Modulation (DPPM) in Optical Wireless Communications

摘要

In this paper, differential pulse-position modulation (DPPM) over an indoor optical wireless link is represented as a Markov source transmitted over a finite-state machine channel. Then, the MAP, Max-Log-MAP and SOVA algorithms are employed for soft-decision decoding of DPPM. The error performance with intersymbol interference is evaluated and compared to hard-decision decoding and MLSD. It is shown that the performance of Max-Log-MAP and SOVA is closed to that of MLSD and MAP with lower complexity.