Low complexity resource allocation in MIMO‒OFDM‒based cooperative cognitive radio networks

Abstract

Abstract A multiple‒input multiple‒output orthogonal frequency division multiplexing based cooperative cognitive radio network is considered in this study, where the cooperation strategy is decode‒and‒forward. The objective is to maximise the capacity of the secondary system while guaranteeing that the interference introduced to the primary system is below the interference temperature limit. The optimal power allocation in the source and the relay is presented and because of the high computational complexity of the optimal approach, a low computational complexity near‒optimal algorithm is further proposed. The joint allocation of the resources in the sub‒optimal algorithm is carried out taking into account the channel qualities, the decode‒and‒forward cooperation strategy and the interference induced to the primary system. The performance of the different approaches and effect of deploying multiple antennas at users are explored through the simulation results. Copyright © 2014 John Wiley & Sons, Ltd.