Abstract: A visible light communications (VLC) system based on non-orthogonal multiple access technology-pattern division multiple access (PDMA), is proposed. PDMA technology can simultaneously optimizes the transmitter and receiver of a multi-user VLC system to achieve non-orthogonal transmission. To achieve the resources reuse at the transmitter under the conditions of frequency domain at the same time, it is necessary to use the joint coding of power, space and channel coding of the multiusers. The multiuser detection at the receiver is, based on message passing algorithm, to optimize the performances of VLC. PDMA can support 150% overload gain of the number of users compared with orthogonal frequency division multiplexing access. Simulation verification of the VLC system is carried out and shows that the transmission distance can achieve 120 cm for the bit error rate of 10^-3 with limited bandwidth of LEDs.

Key words: pattern division multiple access, visible light communication, orthogonal frequency division multiplexing access