Space division multiple access in visible light communications

In this paper, a visible light communication (VLC) system adopting space division multiple access (SDMA) is proposed. In the optical SDMA system, a conventional single-element transmitter is substituted by an angle diversity transmitter which can simultaneously serve multiple active users in different positions. In the simulation, two spatial partition schemes, random grouping and optimal grouping, are implemented which demonstrate the lower bound and the upper bound of the system throughput gain for the optical SDMA system, respectively. The results indicate that the optical SDMA significantly outperforms conventional optical time division multiple access (TDMA). In specific, it has been found that an optical SDMA can achieve over 10 times higher system throughput compared with optical TDMA.