Optimum Device and Modulation Scheme Selection for Optical Wireless Communications

• Published in: Journal of lightwave technology 2021-04, Vol.39 (8), p.2281-2287
• Main Authors: Chun, Hyunchae, Rajbhandari, Sujan, Faulkner, Grahame, Xie, Enyuan, McKendry, Jonathan J. D., Gu, Erdan, Dawson, Martin D., OBrien, Dominic
• Format: Article
• Language: English
• Subjects: Bandwidth; Bandwidths; Detectors; Equalisation; Gallium nitrides; LiFi; Light emitting diodes; micro-LED; Modelling; Modulation; OFDM; optical communications; Optical receivers; Optical sensors; Optical transmitters; Optical wireless; optical wireless communication; Optimization; OWC; RC LED; Signal to noise ratio; technology-curve; visible light communication; VLC; Wireless communication systems; Wireless communications; WLED
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2021.3051379

There has been an extensive modelling of the optical wireless channel, and the optimum modulation scheme for a particular channel is well-understood. However, this modelling has not taken into account the trade-offs that transmitter and receiver selection usually involve. For a particular type of transmitter, the modulation bandwidth and available power are closely related, as are receiver bandwidth, active area and sensitivity. In this article, we present a design approach that takes this device selection into account. The article details a general design method for an optical wireless communication system using a holistic design approach (i.e., considering channel, modulation schemes, and device constraints). The article shows results for particular examples, showing a substantial increase in margin (or data-rate) is available using this approach. For instance, by using this approach mutually optimising both modulation schemes and device constraints, it is found that for an optimally chosen Gallium Nitride micro-LED and a commercial photo receiver pair, a 20 dB SNR margin (or ∼3 times data-rate improvement) can be obtained compared with a more typical approach mainly concerning the modulation scheme optimisation.