LED assessment based on an improved quality factor for LiFi communication

Jean-Paul M. G. Linnartz; Christoph Hoelen; Paul van Voorthuisen; Thiago Elias Bitencourt Cunha; Haimin Tao

doi:10.1117/12.2611453

3 March 2022 LED assessment based on an improved quality factor for LiFi communication

Jean-Paul M. G. Linnartz, Christoph Hoelen, Paul van Voorthuisen, Thiago Elias Bitencourt Cunha, Haimin Tao

Proceedings Volume 12022, Light-Emitting Devices, Materials, and Applications XXVI; 120220F (2022) https://doi.org/10.1117/12.2611453
Event: SPIE OPTO, 2022, San Francisco, California, United States

Abstract

This paper builds a model for the benchmarking and the selection of a suitable LED for wireless optical communication, in particular for indoor LiFi Infrared or visible light communication. It reviews LED measurements and theoretical models for such trade-off and applies these into communication bit-rate throughput expressions. While illumination LEDs are chosen for a large quantum efficiency, for communications also a large 3 dB bandwidth is preferred. In the LED, electron hole pairs recombine radiatively (thereby emitting a photon) or non-radiatively (causing a leakage current and reducing EQE). Non-radiative recombination also contributes to the response speed of the LED and increases its 3 dB bandwidth. On the other hand, a reduction in effective optical power may counterproductively lead to an inadequate signal-to-noise ratio. A trade-off is postulated empirically, in the form of a rule of thumb: “transmit power raised to the power alpha times bandwidth raised to the power one minus alpha” appears to be an LED constant. This semi-empirical model gives straight lines on a log-log scale. This paper searches for a theoretical justification for such a model, where current density acts as a parameter to make the trade-off. According to communication theory, the achievable bit rate grows approximately linearly with an increasing bandwidth but approximately logarithmically with the received energy per bit. However, this needs to be reviewed for a gentle low pass roll-off of the LED response, as it allows modulation far beyond the 3 dB bandwidth. These lead to a perspective on how to operate the LED: a system design faces the challenge to trade-off power versus bandwidth according to the physics LED properties, to optimize a communication throughput target.

Conference Presentation

Citation Download Citation

Jean-Paul M. G. Linnartz, Christoph Hoelen, Paul van Voorthuisen, Thiago Elias Bitencourt Cunha, and Haimin Tao "LED assessment based on an improved quality factor for LiFi communication", Proc. SPIE 12022, Light-Emitting Devices, Materials, and Applications XXVI, 120220F (3 March 2022); https://doi.org/10.1117/12.2611453

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available