Opportunistic Mode Selection and RB Assignment for D2D Underlay Operation in LTE Networks

Device-to-Device (D2D) communication has become an attractive alternative in bringing popular mobile video contents much closer to the end users. However resulting interference caused by the direct communicating D2D pair demands sufficient resources as well as proper admission control mechanisms for the corresponding mode. To resolve these issues, in this paper, we suggest how source and destination end users can optimally select the corresponding operational mode between cellular and D2D modes aiming to maximize the network capacity. Further, we formulate resource block (RB) assignment as an optimization problem and design a deterministic and heuristic algorithm to approximate the optimal solution. The simulation results show a comparison of our proposed optimal and distributed heuristic mode selection with RB assignment algorithms, as well as traditional cellular and underlay D2D mode schemes. From simulation results, we show that our algorithm achieves better average uplink throughput and SINR by reducing interference.