Date Added: May 2012
A cognitive radio is an adaptive, multi-dimensionally aware, autonomous radio system that learns from its experiences to reason, plan, and decide future actions to meet user needs. Due to the technological advancement in last few decades, the people have a magnificent communication setup now-a-days. Cognitive radio is considered to be one of the key issues to give such break -through in communication process. In this paper, the authors are providing a simple yet efficient overview on cognitive radio and the existing research challenges, which will help the researchers around the globe to grab the concept of cognitive radio fast enough and work on it.