Power allocation schemes in optical wireless communication

In this work, detailed literature about the power allocation schemes in optical wireless communication has been presented and discussed. The main goal is to evaluate the Gain Ratio Power Allocation (GRPA) and Normalized Gain Difference Power Allocation (NGDPA) schemes in a 4x4 Multiple-Input Multiple-Output (MIMO) Non-Orthogonal Multiple Access (NOMA) based Visible Light Communication (VLC) system. The work will evaluate the GRPA and NGDPA according to the system's overall achievable sum-rate and the sum-rate gain. The proposed MIMO-VLC system can utilize up to four subscribers regardless of their current position within the system coverage area. The work will examine the received bit rate of each user in different positions within the system coverage area. Target to maintain the same bit rate for each user, especially when the user is at the border of the system coverage area. Finally, the study will discuss the results before and after applying the power allocation schemes GRPA and NGPDA. It has been concluded the overall sum rate gain percentages after applying GRPA are lower than NGDPA, which gives the GRPA allocation scheme an advantage over NGDPA.