Two Stage Spectrum Sensing in Cognitive Radio

Abstract

In past few years the need for high data rate wireless communication has experienced a tremendous growth indicating a huge commercial potential. The growing demand of wireless devices is restricted by the spectrum access policy of radio regulatory regime. Large part of the spectrum is allocated for exclusive use by the licensed users and only a small portion of the spectrum is given for open access. The commercial success of the unlicensed spectrum has encouraged FCC to frame policies towards more flexible and open spectrum access. Most of the licensed bands suffer from under-utilization and less spectral occupancy of spectrum. The exclusive usage criteria in the licensed spectrum have resulted in wastage of limited and precious spectrum. The so called ‘spectrum scarcity’ and ‘limited radio spectrum’ is a result of the way the spectrum is being regulated.