Performance Improvements in Cognitive Radio Networks

In modern wireless communication systems, the number of wireless users is steadily increasing, resulting in a necessary demand for more available radio spectrum. Cognitive Radio (CR) is an innovative solution toward the efficient use of spectrum, by using the same spectrum from Secondary User (SU) simultaneously with Primary User (PU) or exploiting the spectrum holes. In all the cases, important consideration for performance enhancement of secondary user network, is to protect PU's QoS. In this regard all resource management problems and solutions pertaining to normal wireless communications becomes more complicated. In this book two of the important link layer issues, i.e. power control in underlay CR paradigm and cooperate sensing in interweave paradigm are addressed, while considering a regional approach, which generally increases performance than conventional methods, and reduces complexity (and hence cost) than recent techniques/ algorithms.