Performance analysis of a variable‐gain amplify‐and‐forward relayed mixed RF‐FSO system. (23rd August 2017)

• Record Type: Journal Article
• Authors: Khanna, Himanshu; Aggarwal, Mona; Ahuja, Swaran
• Is Part Of: International journal of communication systems. Volume 31:Number 1(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-08-23
• Subjects: channel capacity -- fading -- free space optical communication -- probability of outage -- radio frequency communication -- symbol error rate; Telecommunication systems -- Periodicals; 621.382
• DOI: 10.1002/dac.3400
• Languages: English
• ISSNs: 1074-5351

Abstract

Summary: In this work, an amplify‐and‐forward variable‐gain relayed mixed RF‐FSO system is studied. The considered dual‐hop system consists of a radio frequency (RF) link followed by a free space optical (FSO) channel. The RF link is affected by short‐term multipath fading and long‐term shadowing effects and is assumed to follow the generalized‐ K fading distribution that approximates accurately several important distributions often used to model communication channels. The FSO channel experiences fading caused by atmospheric turbulence that is modeled by the gamma‐gamma distribution characterizing moderate and strong turbulence conditions. The FSO channel also suffers path loss and pointing error induced misalignment fading. The performance of the considered system is analyzed under the collective influence of distribution shaping parameters, pointing errors that result in misalignment fading, atmospheric turbulence, and path loss. The moment‐generating function of the Signal power to noise power ratio measured end‐to‐end for this system is derived. The cumulative distribution function for the Signal power to noise power ratio present between the source and destination receiver is also evaluated. Further, we investigate the error and outage performance and the average channel capacity for this system. The analytical expressions in closed form for the outage probability, symbol and bit error rate considering different modulation schemes and channel capacity are also derived. The mathematical expressions obtained are also demonstrated by numerical plots. Abstract : An amplify‐and‐forward variable‐gain relayed mixed RF‐FSO system is studied where the radio frequency (RF) link follows the generalized‐ K fading distribution, and the free space optical (FSO) channel experiences misalignment fading and gamma‐gamma (GG) faded atmospheric turbulence, apart from path loss. We investigate the error and outage performance and the average channel capacity for this system and obtain the mathematical expressions in closed form for them.