Date Added: Apr 2013
The last decade has witnessed a growing demand for wireless radio spectrum due to the rapid deployment of new wireless devices and applications. Spectrum is a precious resource and thus underutilization of a large part of allocated spectrum is not acceptable. Cognitive Radio (CR) is proposed as a promising solution for increasing spectrum utilization and thereby helping to mitigate spectrum scarcity. CR is capable of sensing the unused spectrum bands and adapts to operate in the vacant bands. Once Cognitive Radios detect the presence of a primary user in their operating band, they must vacate the band immediately. Hence, accurate spectrum sensing is an essential feature of CR systems.