Spectrally efficient TWR-aided free-space optical communication over turbulent channel with generalized pointing error

In this paper, the performance of two-way relay assisted optical wireless communication is analysed. The optical wireless communication system performance is corrupted by atmospheric-induced turbulence and the generalized pointing errors. A three node, dual hop, bi-directional system employing decode-and-forward relaying phenomena are considered. The conventional one-way relay assisted system is spectrally inefficient because of the half duplex losses incurred, whereas the proposed two-way relay assisted system achieves spectral efficiency by managing bi-directional communication in two time slots, thus maximizing the achievable rate of the network. The closed-form expressions of probability density function for composite Gamma-Gamma turbulence impaired by generalized pointing errors are derived. Furthermore, we provide the closed-form expression of cumulative distribution function of the equivalent end-to-end signal-to-noise ratio. In capitalizing on these derived statistics, we conduct outage and error rate analysis of the considered system. Copyright (C) 2016 John Wiley & Sons, Ltd.