Opportunistic Spectrum Access in Imperfect Spectrum Sensing Cognitive Networks

—Spectrum sensing strategy is key to realize cognitive radio. However, spectrum sensing error would affect the access strategy of secondary users in cognitive networks. This paper addresses the spectrum sensing strategy under imperfect spectrum sensing, and proposes opportunistic spectrum access strategies for the imperfect spectrum sensing and fading channels respectively. By setting the optimal operating point of the spectrum detection and updating the confidence vector, we turn the spectrum access optimizations under the imperfect spectrum sensing and fading channels into ones under the perfect spectrum sensing based on the partially observable Markov decision process model. Simulation results show that the strategies proposed could make the secondary users achieve about 10% margin in throughput and the cognitive networks have higher spectrum utilization.