A Cross-Layer Time Slotted Cognitive MAC Protocol

In this paper, using time slotted multiple channels scenario, a cross-layer cognitive MAC protocol is proposed. The proposed scheme senses the radio spectrum and communicates over unused frequency bands. We found that the throughput improvement depends on the transition probabilities. However, considering the past information state of the spectrum can dramatically increases the secondary user's throughput. Moreover, the impact of sensing errors on the MAC layer performance is studied and a sensing strategy, considering the false-alarm and missed-detection probabilities, is investigated. In particular, a joint sensing and scheduling scheme is presented in this work. The objective is to achieve an optimal cross-layer design, spectrum sensing at physical layer and spectrum access at MAC layer, which can enhance the performance of cognitive radio networks. The proposed scheme makes efficient decisions on which channels to sense and access to ensure maximization of the throughput of cognitive radio users. The simulation results have shown that the aggregate throughput can be improved under the constraint that the false-alarm probability does not exceed a specified level.