Energy efficient joint scheduling and resource allocation for downlink cognitive radio networks

This paper investigates the problem of resource allocation in a downlink cognitive radio (CR) network where secondary users (SUs) share multiple channels with the primary user (PU). The aim is to maximize the energy efficiency of the SUs while satisfying the transmit power constraint, the interference power constraint to protect the PU and the minimum rate requirements to guarantee the quality-of-service (QoS) of the SUs. Since the minimum rate requirements of the SUs may not be able to be satisfied, the resource allocation problem may be infeasible. Thus, we propose joint SU scheduling and resource allocation algorithms to solve the problem. Extensive simulations show that the proposed algorithms achieve high energy efficiency and large number of scheduled SUs simultaneously.