A QoS-Based Channel Allocation and Power Control Algorithm for Device-to-Device Communication Underlaying Cellular Networks

—In device-to-device (D2D) communication system, rational resource allocation can effectively reduce the interference between cellular users and D2D users. In this paper, based on the QoS requirement of cellular users and D2D users, we propose a channel allocation and power control optimization algorithm, which takes limit transmission power of each cellular user and total D2D users into consideration when maximizing the system capacity of total D2D users. We can achieve the candidate cellular users set of D2D users according to the minimum SINR requirement of D2D users. And then, the transmission power of cellular users and D2D users are optimized with Lagrange multiplier method, meanwhile we calculate the capacity of each D2D user by optimal power and allocate channel to the D2D pair, which has the maximum value of capacity. However, the optimal algorithm has a high complexity. We further propose a low complexity suboptimal algorithm, which allocates channel and controls power in different stages. Simulation results show that the proposed algorithms effectively improve the capacity of D2D users under the condition of guaranteeing the QoS of cellular users and the suboptimal algorithm greatly reduces the complexity compared with the optimal algorithm.