Throughput optimization MAC scheme for cognitive radio networks: A POMDP framework

Media access control (MAC) protocol plays a very important role in cognitive radio networks (CRN) because it is responsible for decision making on whether to access or not to access the radio spectrum based on the spectrum sensing outcomes. The design of MAC protocols need to achieve the highest spectrum utilization by detecting all spectrum opportunities under fading environment of wireless channel and access without causing interference to primary users (PUs) while maximizing the amount of information transmitted (Throughput). We present in this paper a throughput optimization MAC scheme using cross-layer design concept which integrates the design of spectrum sensing at physical layer and sensing and access strategies at MAC layer while taking into account the channel quality in terms of fading level. We formulate a problem as partially observable Markov decision process (POMDP). Simulation results demonstrate the throughput performance improvement for the proposed scheme using greedy algorithm.