On Signal Quality Measures in Dimmable Visible Light Communications: Definitions and Conversions

This letter suggests the use of signal quality measures that accommodate various signaling configurations in dimmable visible light communications. Although a popular measure of
$E_{b} /N_{0}$
has still been used in the performance analysis of optical transmission techniques, it fails not only to capture essential physical characteristics in optical signals but also to reflect the dimming adjustment feature properly. This letter assesses various alternatives of the quality measure that have been used for optical communication signals and suggests to use a new measure of the ratio of bit peak signal level to noise standard deviation denoted by
$A_{b} /\sigma $
. The proposed measure allows for the joint consideration of code rates and optical channel properties, such as dimming support and signal transmission based on intensity modulation and direct detection.