A MWM relay assignment strategy based on spectrum availability for cognitive radio networks

In cognitive radio networks (CRNs), owing to the restriction of primary users (PUs), the traditional relay assignment based on Shannon channel capacity does not suit to secondary users (SUs). It is necessary to consider spectrum availability when cooperative communication (CC) is carried out in CRNs. In this paper, we propose the concept of Effective Channel Capacity (ECC) according to frequency band occupancy state, and build a Maximum Weighted Matching (MWM) problem where ECC is the weight. Then we find an optimal relay assignment which can maximize global ECC by solving the problem using Kuhn-Munkres (KM) algorithm. The simulation results indicate the necessity of our work for CRNs.