All-optical two-way relaying dual-hop FSO systems using network coding over atmospheric turbulence channel
All-optical two-way relaying is an advanced techniques that helps to improve the data-rate and throughput of free-space optical (FSO) communication systems. In this paper, we propose to implement all-optical two-way relaying in dual-hop FSO systems using network coding. The relay node that is based on optical regenerate-and-forward relaying is equipped with an all-optical XOR gate and optical hard-limiters. Performance of the proposed system is analyzed under the effect of atmospheric turbulence and noise induced by the background light. Based on the closed-form expression for bit-error-rate (BER) derived in this paper, the numerical results demonstrate the feasibility of the proposed systems. In addition, the numerical results provide the useful information for system design such as optimum range of threshold power, required transmitted power, and supportable transmission distance.