Performance analysis and implementation of biased MC-PPM for optical energy transfer and communication system

This paper investigates a new modulation technique, Biased multi-coded pulse position modulation (Biased MC-PPM), suitable for simultaneous lightwave information and power transfer (SLIPT) systems to overcome the limitations of energy harvesting efficiency in conventional light emitting diode (LED)-based modulation schemes. This technique utilizes direct current biasing to control the dimming levels and is compared with multi-coded variable pulse position modulation (MC-VPPM) and $M$-ary variable pulse position modulation (VPPM), which use pulse width modulation for dimming control. In Biased MC-PPM, the binary signal is first converted into an orthogonal code, and then the final signal is generated using a Biased PPM mapper. The generated signal is transmitted through an LED and received by a solar cell. Compared to MC-VPPM and $M$-ary VPPM, the Biased MC-PPM demonstrates slightly lower communication performance, but it proves to have higher energy transfer efficiency in visible light communication and free-space optical environments. Therefore, Biased MC-PPM presents a promising solution for SLIPT systems, where energy efficiency is a primary concern.