Optimization model of a wireless optical system with pulse position modulation

In a near-ground outdoor (NGOD) environment, a wireless optical communication system usually uses pulse position modulation (PPM) since it provides better power efficiency than on-off keying modulation. In the literature, schemes based on non-return-to-zero PPM have been investigated. We extend this work to a return-to-zero (RZ) PPM scheme with a NGOD application. As a case study, we develop an optimization model to maximize the transmission distance based on a RZ-4PPM system. We show that, with the reduced pulse duration, the transmission distance can be further improved. The model involves three different Gaussian terms, and details of the solution procedure are included.