Cyclic Multiplexer and Transmitter Diversity Based Hybrid PON-FSO System for RB Noise and Inter-Channel Interference Suppression

Hybrid passive optical network (PON) and free space optical communication (FSOC) systems have emerged as the ultimate solution to long-range and cost-effective operations. In bidirectional PON systems, where wavelength reuse is performed, a predominant limitation emerges, such as Rayleigh backscattering (RB) noise. Also, in WDM-PON networks, bit error rates (BER) increase due to inter-channel interference inside optical fiber. Therefore, in this work, a bidirectional 160 Gbps high capacity hybrid PON-FSO system is proposed for a 20 km wired and 10 m wireless distance. A cyclic multiplexer is employed to reduce the RB noise and transmitter diversity (Non return to zero in downstream and alternate mark inversion in upstream) is used to reduce inter-channel crosstalk in the proposed system. Results revealed that the proposed system offered better results with the incorporation of cyclic multiplexer and transmitter diversity.