Perfect Decomposition Narrow-Band FIR Filter Banks

This brief introduces perfect decomposition filter banks based on narrow-band linear-phase finite impulse response (FIR) filters. They consist of inner and lateral FIR filters. The inner filters are optimal equiripple narrow-bandpass FIR filters based on isoextremal polynomials. The inner filters are supplemented by lateral narrow-band low- and high-pass FIR filters. The concept of such isoextremal polynomials of this kind enables flexibility in the resulting frequency response of the filter bank. The filter banks presented here are made under the constraint of the resulting frequency response with a constant value for all frequencies.