Space division multiple access in optical attocell networks

In this paper, an optical space division multiple access (SDMA) scheme is proposed for optical attocell networks. In the system, a conventional single-element transmitter in each optical cell is substituted by an angle diversity transmitter which can simultaneously serve multiple active users at different positions. This type of configuration can increase the available bandwidth resource and also mitigate inter-cell interference (ICI) in optical attocell networks. The results indicate that the optical SDMA scheme significantly outperforms the conventional optical time division multiple access (TDMA) scheme. The SDMA schemes is shown to improve the average spectral efficiency of the system by a factor of 26 for a 37-element light-emitting diode (LED) angle diversity transmitter. Finally, the study is extended to account for user position errors. The Monte-Carlo simulation results show that the system is very robust to user position errors.