Decode-and-forward relaying in mixed [eta] - [mu] and gamma-gamma dual hop transmission system

• Published in: IET communications Vol. 10; no. 14; pp. 1769 - 1776
• Main Authors: Sharma, Nikhil, Bansal, Ankur, Garg, Parul
• Format: Journal Article
• Language: English
• Published: 20.09.2016
• Subjects: Channels; Computer simulation; Ergodic processes; Exact solutions; Links; Mathematical analysis; Monte Carlo methods; Relaying
• ISSN: 1751-8628; 1751-8636
• DOI: 10.1049/iet-com.2015.0992

In this study, the authors carry out the performance analysis of an asymmetric dual hop relay system composed of both radio-frequency (RF) and free-space optical (FSO) links. The RF link is subject to generalised [eta]- [mu] distribution, while the channel for FSO link is modelled as gamma-gamma distribution. The decode-and-forward relaying phenomena is used, where the relay decodes the received RF signal from the source and converts it into an optical signal using the sub-carrier intensity-modulation (SIM) scheme for transmission over the FSO link. The FSO link is subjected to pointing errors and account for both types of detection techniques, i.e. IM/DD and heterodyne detection. Novel exact closed-form expressions for the probability density function and cumulative distribution function of the equivalent end-to-end signal-to-noise ratio of the mixed RF/FSO system in terms of Meijer's G function are derived. Capitalising on these derived channel statistics, they provide the new closed-form expressions of outage probability and the ergodic channel capacity. They also provide the average bit-error rate for different binary modulations. Furthermore, the Monte Carlo simulations validate the analytical results.