Deployment of Hybrid FSO/RF Links in Backhaul of Relay-Based Rural Area Cellular Networks: Advantages and Performance Analysis

Abstract

In this paper, we consider a rural area cellular framework in which a relay based free space optical (FSO) configuration is assumed for the backhaul. We assume orthogonal frequency division multiple access setting for both optical and radio frequency (RF) links. In this system, the rural users communicate with base station (BS) through several relays while the links between BS and relays are assumed to be hybrid FSO/RF. We then propose a resource allocation scheme to maximize the system throughput and compare the performance against a similar system that uses only an FSO link in the backhaul. Simulation results show that deploying hybrid FSO/RF communication considerably improves the performance. The improvement is more pronounced in foggy conditions. As far as the number of deployed relays to maintain a certain performance is concerned, we observe that a hybrid FSO/RF system needs considerably smaller number of relays, as few as half in our case, than an FSO system.

Multi-User Mixed FSO-RF Systems With Aperture Selection Under Poisson Field Interference

“…Notice in (36) that G d stands for the diversity gain and is defined as the slope of the asymptotic curve, and G c is the coding gain representing the SNR advantage of the asymptotic curve relative toγ −G d reference. Comparing (35) with (36), the achievable diversity gain is expressed as…”

“…Considering the effect of outdated channel state estimation of the RF links, the authors in [34] studied the outage and error rate performances of an AF mixed RF-FSO relay network with generalized order relay selection. An optimization problem was formulated in [35] to maximize the throughput of a multiple-relays multiple-destinations AF orthogonal-frequency-division-multiplexing (OFDM) mixed RF-FSO relay network through resource and power allocations for the OFDM subcarriers. A similar optimization problem was formulated in [36] to maximize the throughput of a DF mixed RF-FSO relay network with both conventional and buffer-aided relays.…”

Free-space optics mode-wavelength division multiplexing system using LG modes based on decision feedback equalization

“…Based on these advantages, FSO has emerged as a promising solution for the last mile bottleneck considering the scarcity of radio bandwidth despite various approaches for optimization of the radio spectrum [2,3]. FSO also offers an alternative transmission medium to fiber optics for rural and geographically-challenged locations where cabling may be an issue [4].…”

A Head/Taillight Featuring Hybrid Planar Visible Light Communications/Millimetre Wave Antenna for Vehicular Communications

“…Hybrid optical-radio frequency wireless technologies are an attractive solution for reliable outdoor communication links. They ensure reliability in all weather conditions whilst simultaneously relieving the pressure on radio frequency (RF) spectral usage at low cost and low complexity [1,2]. As a result, optical/RF hybrid systems have become the focus of ever-increasing attention in recent years.…”