A Novel Adaptive Resource Allocation Algorithm for Multiuser OFDM-Based Cognitive Radio Systems

Cognitive radio(CR) is a concept to improve the utilization of scarce spectrum resources in wireless communication, and orthogonal frequency division multiplexing (OFDM) is regarded as the best technology to match with the CR systems. In this paper, a new adaptive resource allocation algorithm for OFDM CR systems is presented. This algorithm solves the optimization problem based on maximize the total transmit bit rates of secondary users, on the one hand, the total transmit power of secondary users should below the transmit power constraint, on the other hand, the interference to primary users should under the maximum interference level, then allocate sub channels by an improved Hungarian Algorithm, and load bits and power by greedy algorithm. Simulation results show that the proposed algorithm can improve the system throughput comparing with some other sub optimal algorithms.