Algorithm 1: Overview of the proposed heuristic-based solution.

Binding of users to LEDs: Assign users to different LEDs in such a way that a user cannot be assigned to more than one LED; Determining the user-pairs for each LED: Apply the D-NLUPA algorithm to determine the user-pairs per LED. Store the user-pairs in $\mathsf{\Gamma }\left(l_i\right)$; Optimizing subcarrier(s) allocation to user-pairs in each LED and power allocation within each pair: This task allocates the subcarriers to the user-pairs to maximize the minimum achievable rate of the served users. We apply the SA algorithm with an innovative objective function that allocates the users-pairs to the subcarriers while ensuring an almost uniform data-rates for all the served users.