Abstract
Visible-light communication systems are suitable to realize secure indoor networks. In this paper, a visible-light CDM experimental system developed by the authors with an FPGA and white LEDs is reported. The developed system adopts EWO signaling scheme as an MUI canceller. The signature codes can be selected from MPSCs and inverted MPSCs with a code length of 16. It has five channels on each of which 31.25kHz MIDI data spread with a code sequence is transmitted. The experimental system has five LEDs to transmit coded sequences with a chip rate of 500kcps. Multiplexed optical signal sequence is received by the receiver and decoded by each of five EWO decoders. It has been shown that the average light intensity of the system employing an inverted MPSC with a length of q^2 is, theoretically, q-1 times as high as that of the system employing a non-inverted MPSC with the same length. It is shown that experimental results about light intensity obtained with the developed system agree well with the theoretical results.
https://ror.org/02f0psx94 
