Experimental validation of multiple gain combiner in single-relay cooperative FSO communication systems

In this paper, we have proposed a new combining technique named as multiple gain combiner (MGC) for single-relay cooperative FSO communication systems. The first objective of this paper is to test the experimental feasibility of single-relay cooperative FSO communication system. The next objective is to ascertain the performance of a cooperative FSO link in the presence of simulated fading effect generated by means of modified optical chopper. The last objective is to determine the performance improvement of our proposed MGC combining method over conventional equal gain combining method. Bit error rate performance of the relay system is tested for single-relay cooperative FSO link under weak and strong fading conditions simulated with the modified optical chopper, which shows that the significant performance improvement can be obtained with the use of cooperative diversity. Rsoft-Optsim with MATLAB^® co-simulation results show the same trend of performance for the same level of fading present in the system, thereby validating the fading mechanism as obtained by means of modified optical chopper.