Performance Analysis of Dicode Pulse Position Modulation for Optical Wireless Communications

This paper introduces a modulation scheme, dicode pulse position modulation (DiPPM) for optical wireless communications using intensity modulation with direct detection (IM/DD). The modulation structure of DiPPM and expressions for the bandwidth-utilization efficiency, average optical power requirement and packet error rate (PER) are presented. We show that there is a built-in error checking-out performance in DiPPM, and the PER performance for DiPPM can be improved about 3 dB by using automatic repeat request (ARQ) when an error is detected. And numerical simulation results show that, compared with OOK and 2-PPM, DiPPM displays lower packet error rate and higher power efficiency, compared with higher order PPM (bit resolution M > 2), DiPPM displays lower power efficiency and higher packet error rate but less bandwidth requirement.