Simulation of Optical Homodyne Coherent Receiver for Inter-Satellite Links

Coherent communication is one of the most favored technique for optical satellite communications as it offers data rates which are high and lesser Bit Error Rates (BER) along with the highest receiver sensitivity and full signal recovery, but with a carrier recovery system at the receiver. The Costas loop is a most popular phase locked loop used in almost all coherent receivers where the carrier synchronization is an important aspect. This paper has a mathematical approach to the design of Costas loop for each modulation scheme considering the bitrate of 2.5Gbps and the optical source. The theoretical approach as well as simulations both are discussed. Simulations are carried out in using Opti system software tool and the results such as the eye diagram and the constellation diagram are discussed.