Unified Performance Analysis of Mixed Radio Frequency/Free-Space Optical Dual-Hop Transmission Systems

Abstract

The mixed radio frequency (RF)/free-space optical (FSO) relaying is a\npromising technology for coverage improvement, while there lacks unified\nexpressions to describe its performance. In this paper, a unified performance\nanalysis framework of a dual-hop relay system over asymmetric RF/FSO links is\npresented. More specifically, we consider the RF link follows generalized\n$\\kappa$-$\\mu$ or $\\eta$-$\\mu$ distributions, while the FSO link experiences\nthe gamma-gamma distribution, respectively. Novel analytical expressions of the\nprobability density function and cumulative distribution function are derived.\nWe then capitalize on these results to provide new exact analytical expressions\nof the outage probability and bit error rate (BER). Furthermore, the outage\nprobability for high signal-to-noise ratios and the BER for different\nmodulation schemes are deduced to provide useful insights into the impact of\nsystem and channel parameters of the overall system performance. These accurate\nexpressions are general, since they correspond to generalized fading in the RF\nlink and account for pointing errors, atmospheric turbulence and different\nmodulation schemes in the FSO link. The links between derived results and\nprevious results are presented. Finally, numerical and Monte-Carlo simulation\nresults are provided to demonstrate the validity of the proposed unified\nexpressions.\n