In all the papers and books that I read, only the DC channel gain of the VLC system is studied without any further justification. How can we know for sure that the channel doesn't affect the frequency of the light? What would the spectrum of the channel look like with an LED modulated in OOK?
VLC (Visual Light Communication) is the generic term for information sharing by optical means and OOK is not a verbal comment as on Terry Pratchett’s Discworld, it refers to information bit generation by On/Of Keying. Cleary OOK will generate a precise square waveform. A substantial amount of data may be carried within each such pulse by modulating either the DC gain values or the oscillation frequency.
For more information on OOK spectra see:-
Digital Modulation - One bit at a time - University of St Andrews
https://www.standrews.ac.uk/~www_pa/Scots_Guide/RadCom/part19/page1.html
As a further comment, I fundamentally deplore the use of three letter acronyms such as VLC and OOK. In origin they hark back to the era when on-line text space was at a premium. In a modern context they serve only to obstruct clear communication and boost the egos of correspondents who seek to be perceived as experts. We are not alone in this affliction, it is evident throughout the full range of communication technology.
My plea to all RG users is that they return to plain English and refer to ‘visual light communication’ and ‘on/off keying’. Firstly it makes your text much more readable. Secondly, (and probably more importantly} the cohort of those who read understand and cite you work will be significantly enhanced. Finally, I suggest that it could open access to new ideas; to alternative lines of communication, and to new research projects.
Mr David Oulton
Thank you for your answer but the link doesn't seem to work. However, you are right for the use of acronyms. I usually define them and I must have written my question too quickly. I would like to add that LED means Light Emitting Diode and DC Direct Current.
To be sure I fully understand your answer, you mean that we only consider the DC gain when studying the channel because the DC gain is modulated?
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