Abstract:
Recently, visible light communication networks have emerged as a possible option for data ac cess, primarily for indoor environments. The very high data rates, free from radio frequency
interference, and low implementation cost behavior make them attractive for the next generation
of indoor networking. But visible light communication technology supports only short-range
data transmission, and hence the achievable data rate decreases rapidly with increasing distance
between the transmitter and receiver. Additionally, developing a high data rate link in VLC
system is difficult due to the narrow modulation bandwidth of LEDs. So that, it is essential to
apply MIMO and Non-orthogonal Multiple Access to overcome such problems.
In this thesis, a low complexity and efficient power allocation strategy was proposed for in door downlink MIMO-based visible light communication systems. Non-Orthogonal Multiple
Access was applied on MIMO-VLC system to improve performance of edge users. Gener ally, the performance of the total sum rate of 4 × 4 MIMO VLC of k number of users were
analyzed. Specifically, the sum rate, the sum rate gain, and the achievable rate of uniformly
distributed users were analyzed for different power allocation techniques. MATLAB simula tion results depicted that the effectiveness of the proposed power allocation strategy than gain
ratio power allocation schemes and normalized gain difference power allocation schemes for
the large number of users. The proposed NOMA, NGDPA, and GRPA achieved a sum rate of
261.89 Mbit/s, 235.28 Mbit/s and 152.27 Mbit/s respectively at the edge of the system for six
users. More specifically, the proposed NOMA attained an achievable sum rate of 18.36% and
65.98% as compared with the NGDPA approaches, and GRPA approaches in the 4×4 MIMO
based visible light communication networks with eight uniformly distributed users. The future
works can focus on finding the optimal user grouping and allocating power to each group. Ad ditionally, allocating the power according to quality of service is an open research problem in
MIMO-NOMA-based VLC networks.
