Spectrum Sensing in multipath fading channels using Cosine Modulated Filter Bank for Cognitive Radio applications

In this paper, an elegant scheme for Spectrum Sensing (SS) in fading channels with Cosine Modulated Filter Banks (CMFBs) and energy detection method is proposed. Filter Bank Spectral estimators (FBSEs) are used as it allows sensing multiple subbands simultaneously. In fading channel conditions, the received signal also impaired with AWGN noise is equalized at the receiver and then sensed through Cosine modulated Spectral estimators. The energy detection is performed at the subband outputs of the CMFB. Spectral holes can be detected with high confidence due to spectral containment of cosine modulation in subband sensing. This method provides the flexibility to detect active signals in a fading environment. Simulations are done with Zero Forcing Equalizer (ZFE) and Minimum Mean Square Error (MMSE) equalizers and the results are compared.