Abstract
Providing network access for multiple users in a visible light communication (VLC) system that utilizes
white light emitting diodes (LED) as sources requires new networking techniques adapted to the lighting features. In
this paper we introduce two multiple access techniques using expurgated PPM (EPPM) that can be implemented using LEDs
and support lighting features such as dimming. Multilevel symbols are used to provide
$M$
-ary signaling for multiple users using multilevel EPPM. In the first technique, the
$M$
-ary data of each user is first encoded using an optical
orthogonal code assigned to the user, and the result is fed into a EPPM encoder to generate a multilevel signal. The
second multiple access method uses subsets of the EPPM constellation to apply MEPPM to the data of each user. While
the first approach has a larger Hamming distance between the symbols of each user, the latter can provide higher
bit-rates for users in VLC systems using bandwidth-limited LEDs. Both techniques are able to support up to 15
simultaneous users transmitting 200 Mb/s with a bit error rate of
${10}^{-3}$
under normal lighting conditions.
© 2013 IEEE
PDF Article
More Like This
Cited By
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Login to access Optica Member Subscription