New Adaptive Resource Allocation Algorithm for Multiuser OFDM-based Cognitive Radio Systems
Zhu Qi · Jisuanji fangzhen · 2012
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.A dynamic resource allocation algorithm for OFDM CR systems was proposed.This algorithm solved the optimization problem based on maximizing the total transmit bit rates of secondary users,on the one hand,the total transmit power of secondary users should be below the transmit power constraint,on the other hand,the interference to primary users should be under the maximum interference level.The subchannels were allocated by an improved Hungarian Algorithm based on a new cost function,then,the bits and power adaptively were allocated based on requirement of secondary users.Simulation results show that the proposed algorithm could effectively use spectrum holes and improve the system throughput with the constraint on every primary user.