SPECTRUM SENSING BY CYCLO-STATIONARY DETECTOR

The key challenge of spectrum sensing is the Detection of weak signals or primary user in noise with a very small probability of miss detection, which requires better understanding of very low SNR regimes. Cognitive radio allows unlicensed users to access licensed frequency bands through dynamic spectrum access so as to reduce spectrum scarcity. The spectrum sensing problem has gained new aspects with cognitive radio and opportunistic spectrum access concepts. It is one of the most challenging issues in cognitive radio systems; the paper explains sensing concept and its various Techniques. First cognitive radio standard called the Wireless Regional Area Network (WRAN). In additional to conventional PHY and MAC layer functionalities, new features have been included in IEEE 802.22 standards. These features are Spectrum Sensing and Spectrum Management.