A FPGA Implementation of Adaptive PPM Modulation Schemes for Wireless Optical Communication

Wireless optical communication is the current research topic in high data rate data communication area.It is under research to utilize in under water sensor network communication and free space optical communication. Mainly PPM modulation scheme is used in FSO because of it high power efficiency ,transmission efficiency and strong anti jamming capability. One of the key difficulties of implementing PPM technique is that the receiver must be properly synchronized to align the local clock with the beginning of each symbol. Therefore, it is often implemented differentially as differential pulse-position modulation. In this paper various PPM modulation schemes like single pulse position modulation, multi pulse position modulation, diffential pulse position modulation schemes are going to implemented in FPGA and its space requirement, time complexity and power consumption are going to analyzed. This implementation is also concern with an adaptive selection of modulation scheme based on channel condition ,for this feed back received from receiver based on bit error rate.