A New Flexible Filter Bank for Low Complexity Spectrum Sensing in Cognitive Radios

Conventional filter bank-based spectrum sensing methods employ uniform discrete Fourier transform filter bank (DFTFB). In this paper, we propose a multi-stage coefficient decimation filter bank (MS-CDFB) for wideband spectrum sensing in cognitive radios. From an initial fixed-coefficient modal filter, a filter bank that has multiple passbands of either uniform or different passband widths can be obtained using coefficient decimation. Design examples show that proposed MS-CDFB offers a complexity reduction of about 30% over the DFTFB while giving a superior sensing accuracy than the latter. The complexity reduction of MS-CDFB over the DFTFB is 85%, if both the spectrum sensors are designed to produce identical sensing accuracies.