A review on recent advances in spectrum sensing, energy efficiency and security threats in cognitive radio network

In the last decade there is a vast development in the wireless communication and new wireless devices so the demand of the radio spectrum is increasing, There is a need of efficient spectrum utilization because due to fixed assignment policy a huge portion of licensed spectrum is underutilized. To exploit the radio spectrum in a more intelligent and flexible way, regulatory bodies are reviewing their policies by adopting innovative communication technology. Cognitive Radio is a revolutionary technology which enables access to underutilized spectrum efficiently and dynamically without causing interference to the licensed users. In the last few years there has been significant development in cognitive radio technology. This paper reviews recent development and advances in three key areas of cognitive radio network - spectrum sensing, security and energy efficiency. In this paper the fundamentals of cognitive radio is first discussed and than existing work is reviewed.