Joint-Greedy Allocation Algorithm on D2D Communication Underlaying Networks

The fifth generation (5G) network introduce D2D communications on cellular network. On D2D system, the device can communicate each other directly without using the eNB, with limited range. This D2D network can be superimposed on LTE cellular network and will use same resources with the existing cellular users. The interference will happen between D2D users and the existing cellular users. To maintain the system performances, the resources allocation process become the important aspect, because of the interference among users. This work proposed joint-greedy algorithm, a greedy based allocation algorithm to assign the resources to D2D users for communications process. Join-greedy algorithm consists of two phase of sorting to find the best resource for each D2D users. The first sorting process is to find the best resource for each D2D user, and the second sorting process is to find the best solution from first process result. From the simulation process, the proposed algorithm can improve the spectral efficiency up to 0.309 bps/Hz, and improve the energy efficiency by 12.67 kbps/Watt. The proposed algorithm also can maintain the fairness among D2D pair. Join greedy algorithm has the average fairness index 79.05%. This prove that the proposed algorithm has better system performances compared with the other algorithm.