Cognitive radio spectrum sensing: A survey

Cognitive Radio (CR) is a promising technology to improve the spectrum utilization efficiency. Due to the increasing demand for wireless communication CR allows better use of the radio spectrum. CR is intelligent network that adapt to the changes in spectrum environment. The main aspect of the cognitive radio is spectrum sensing. It is one of the most challenging issues in cognitive radio systems. In this paper, a survey of spectrum sensing techniques for cognitive radio is presented. Various sensing scheme for the cognitive radio are reviewed and the challenges associated with it. The paper describes the cooperative and signal processing sensing techniques and their various forms.