Title
A Relay-Assisted OFDM System for VLC Uplink Transmission
Abstract
Uplink transmission is an issue for visible light communications due to the unpleasant irradiance from the source light when placed close to the users. To overcome this problem, this paper proposes the use of relays to lower the required source optical power. A popular multi-carrier modulation scheme, termed direct-current biased optical orthogonal frequency division multiplexing, is employed to achieve high spectral efficiency. In addition, both amplitude-and-forward (AF) and decode-and-forward (DF) protocols are used. The theoretical models of AF and DF protocols are also obtained and verified by simulations. To minimize the source optical power while satisfying reliable communications, this paper formulates the associated optimization problems for AF and DF protocols. Exhaustive search is first used to obtain the optimal configuration for the system. As exhaustive search requires high computation efforts and can be time-consuming, two low-complexity suboptimal designs for AF and DF protocols are then proposed, and the proposed suboptimal designs can approximate the performance of exhaustive search in high signal-to-noise ratio regions. Numerical and experimental results indicate that when compared with the counterpart without a relay, the proposed relay-assisted system requires much lower source optical power under the constraints of reliable transmissions.
Year
DOI
Venue
2019
10.1109/TCOMM.2019.2923237
IEEE Transactions on Communications
Keywords
Field
DocType
Relays,Uplink,Protocols,OFDM,Light emitting diodes,Optical fiber communication,Optical receivers
Optical power,Brute-force search,Computer science,Visible light communication,Electronic engineering,Modulation,Optimization problem,Relay,Orthogonal frequency-division multiplexing,Telecommunications link
Journal
Volume
Issue
ISSN
67
9
0090-6778
Citations 
PageRank 
References 
1
0.35
0
Authors
5
Name
Order
Citations
PageRank
Yang Yang1612174.82
Zhimin Zeng217435.45
Julian Cheng31409145.12
Caili Guo416634.00
Chunyan Feng530538.57