Aashish Mathur, PI / SERB / Completion in 2022

Free space optical (FSO) communication deals with the transmission of information in an optical carrier from the source to the destination via atmosphere. FSO links are appealing for applications such as last-mile access, backhauling services, and high data-rate transmissions. However, the performance of FSO communication system is severely affected by atmospheric conditions such as fog and snowfall, atmospheric turbulence, pointing errors (PEs) which include boresight and jitter, background radiation, thermal noise and shot noise. This project aims at improving the performance of FSO systems using hybrid automatic repeat request (HARQ) technique which is a link layer technique that combines channel coding with ARQ scheme. Experimental set-up to emulate the actual atmospheric turbulence under laboratory controlled environment will be developed that will be very useful for future researches in FSO domain. Physical layer security has been very limitedly explored in FSO literature. The secrecy performance of FSO systems under correlated Málaga turbulence will be analyzed in this project in terms of different metrics such as average secrecy capacity, secrecy outage probability, and strictly positive secrecy capacity which will clearly indicate the effect of boresight PEs and the eavesdropper (Eve) location. Thus, physical layer security issue will be addressed to ensure secure transmission to legitimate receiver (Bob) over FSO communication links in the presence of eavesdropper.