Secrecy Based Resource Allocation for D2D Communication Using Tabu Search Algorithm

Device-to-device (D2D) communications have been pro- posed as one of the key technologies to improve the spectral efficiency in the future fifth generation (5G) of wireless mobile communication systems through resource sharing with cellular networks such that it can offload the part of cellular traffic onto the D2D network. However, intra-cell interference in D2D underlying cellular systems may decrease the performance of wireless network. In this paper, we investigate the subcarrier allocation issue when employing physical layer security capacity of D2D pairs and cellular users (CUs). When secrecy-capacity take into consideration, D2D communications can help the cellular system to decrease intra-cell interference. In our optimization task, we formulate the subcarrier allocation problem to maximize the system secrecy-capacity while guaranteeing the minimum data rate requirements for all D2D pairs and CUs. Such optimization is NP-hard problem with nonlinear constraints and optimal solution can be found through complicated methods such as exhaustive search or branch-and-bound. We, therefore, propose tabu search (TS) meta-heuristic algorithm to globally find the optimal subcarrier allocation solution to maximize system secrecy-capacity. Simulation results show that the proposed TS scheme achieves a higher performance than other algorithms in term of system secrecy- capacity.