Efficient Discovery of Spectrum Opportunities with MAC-Layer Sensing in Cognitive Radio Networks

摘要: Sensing/monitoring of spectrum-availability has been identified as a key requirement for dynamic spectrum allocation in cognitive radio networks (CRNs). An important issue associated with MAC-layer sensing CRNs is how often to sense the availability licensed channels and which order those channels. To resolve this issue, we address (1) maximize discovery opportunities by sensing-period adaptation (2) minimize delay finding an available channel. Specifically, develop optimization mechanism optimal channel-sequencing algorithm, well environment- adaptive channel-usage pattern estimation method. Our simulation results demonstrate efficacy proposed schemes its significant performance improvement over nonoptimal schemes. The discovers more than 98 percent analytical maximum discoverable spectrum-opportunities, regardless number sensed. For scenarios tested, scheme shown discover up 22 schemes, may become even greater proper choice initial periods. idle-channel technique ranges from 0.08 0.35 seconds under tested scenarios, much faster Moreover, our method track time-varying channel-parameters accurately.