Design and performance analysis of spectral-efficient hybrid CPDM-CO-OFDM FSO communication system under diverse weather conditions

Abstract

Abstract A comprehensive design is proposed for the free-space optical (FSO) communication system by hybridizing circular polarization division multiplexing (CPDM) with coherent optical orthogonal frequency division multiplexing (CO-OFDM) and its performance is investigated realistically under diverse turbulent weather conditions of Bangladesh. Here, we consider Gamma–Gamma distribution for the turbulent FSO channel model. Moreover, the proposed scheme presents an excellent performance since the CPDM technique not only maximizes the link capacity of the FSO system but also enhances the spectral efficiency of the system. Besides, multipath fading, which is appeared during the FSO transmission, is significantly mitigated by OFDM modulation. The outcomes from the simulation confirm the advantages of the proposed hybrid scheme and also it can serve as a reference for the FSO application even in turbulent weather conditions. Performance analysis of the proposed model is described in terms of the optical power spectrum, optical signal-to-noise ratio, bit error rate, Q factor, constellation diagrams, and eye diagrams.