Performance Analysis of RZ-PPM Coding in Optical Wireless Systems

A number of modulation techniques have been proposed and studied for the successful of the operation Ground-Ground wireless optical communication. Each modulation scheme has its advantages and drawbacks. The PPM (Pulse Position Modulation) had shown to be desirable for its power efficiency. In this paper, we discuss the use of RZ-PPM (Return-To-Zero PPM) and Non-Return-To-Zero (NRZ PPM) modulation techniques for free space optical communications systems.The results show that RZ-PPM shows more power efficiency at expense of a degradation in terms of spectral efficiency.