A new algorithm for joint sensing and power allocation in multiuser cognitive radio networks

In this paper, we propose a new two phase algorithm to maximize the downlink throughput of a cognitive radio network (CRN) using OFDMA. Since we consider a multiuser CRN, subcarrier assignment should be performed for secondary (unlicensed) users. In Phase I of the proposed algorithm, first a coarse spectrum sensing and equal transmitted power allocation are considered and then subcarrier assignment is done. In phase II, a fine spectrum sensing and power allocation are performed. Instead of applying thresholds, we estimate and use the number of occupied subchannels for fine spectrum sensing. Simulation results show that our proposed algorithm provides better suboptimal solutions with much lower complexity.