An Exact Error Analysis of Multi-User RC/MRC Based MIMO-NOMA-VLC System With Imperfect SIC

Visible Light Communication (VLC) has appeared as a breakthrough technology for beyond 5G networks by delivering a broad license free spectrum. In this paper, multiple input multiple output (MIMO) technique is implemented with non-orthogonal multiple access (NOMA-VLC) system in order to develop a robust error-free high rate network for a multi-user scenario. In particular, a generalized multi-user MIMO-NOMA-VLC system with
$M\times N$
line-of-sight (LOS) links per user is proposed which adopts on-off keying (OOK) modulation for data transmission. A novel closed form expression of probability of error for the proposed system is derived considering a practical scenario of imperfect successive interference cancellation (SIC). This paper also presents the detailed analysis of a three user
$2\times 2$
MIMO-NOMA-VLC system and an exact closed form expression of probability of error of this system is derived. The three user
$2\times 2$
MIMO-NOMA-VLC system completely outperforms the single input single output (SISO) NOMA-VLC system with same set of parameters. The error performance of the proposed system enhances as the number of photo detectors (PDs) at each user increases. A three user
$2\times 2$
MIMO-NOMA-VLC system ensures the best performance at the power allocation co-efficient of 0.3. The error performance of the proposed system is investigated for the parameters of interest, i.e., distance between the transmitting LEDs and distance between the receiving PDs at each user terminal. The derived probability of error expressions are verified with the simulation results.