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DISCRETE WAVELET TRANSFORM BASED SPECTRUM SENSING IN COGNITIVE RADIOS USING EIGEN FILTER

In the developing world, the usage of Mobile phones and other data communication devices are unavoidable which results in the congestion of Spectrum. Recent studies have showed that nearly 70% of spectrum was unused most of the time. The band width becomes expensive due to shortage of frequencies. Therefore to use the spectrum effectively, we need to identify whether the spectrum is occupied or not. Cognitive Radio is a technology which helps us to use the spectrum effectively. Spectrum Sensing is one of the techniques in cognitive radio. Energy detection, Feature detection and Matched Filter detection are methods used for spectrum sensing. In the proposed method, Discrete Wavelet Transform (DWT) is used to identify the unused spectrum band in the RF spectrum. This will yield better results and fast sensing than the conventional method. Moreover, Eigen filter is used in the filter banks of wavelet to give high resolution outputs.