Channel selection and power allocation for device-to-device enabled cellular networks

Cellular networks with device-to-device (D2D) communication capabilities offer increased spectrum utilisation and system throughput. However, these performance gains depend on the channel and power allocation strategy used. In this study, the authors have chosen underlay D2D as it is more advantageous in terms of spectrum efficiency, but introduces additional interferences. To cope up with these challenges, they propose new channel assignment and power allocation schemes with and without Quality of Service (QoS) constraint for D2D pairs. The authors' schemes allow multiple channels to be shared by each D2D pair without degrading the performance of the existing cellular system. First, they formulate the joint channel and power allocation problem without considering the QoS for D2D pairs which results in a non-convex mixed-integer non-linear programming problem and cannot be solved in polynomial time. Then, the problem of channel and power allocation is reformulated and optimised, individually. Following this, they introduce QoS constraints for each D2D pair by specifying the minimum number of channels that should be allocated to each D2D pair during the assignment. The effectiveness of their scheme is verified through numerical results.