Dynamic spectrum access with two channel sensing in cognitive radio networks

In this paper we present a novel dynamic spectrum sensing and access model in cognitive radio networks. This model allows secondary users (SUs) to sequentially sense two channels in a single time slot and provides coordinated access of multiple SUs to the available channels. The presented access model is formulated as a channel assignment optimization problem which is shown to be NP-hard. We subsequently propose and analyze a Markov chain based greedy channel assignment scheme (MCGA) which allows for sequential sensing of two channels with a priority order per time slot. Finally, we analyze and evaluate the performance of our approach in a saturated network. Our analytical results, validated by simulation, indicate that compared to the existing work, our approach can achieve significant improvements in terms of SU throughput and MAC delay.