On the synthesis of nonsymmetric and nonuniform filter banks

A new type of nonuniform filter bank is presented. Filter banks divide the frequency range into a number of bands. The authors´ filter bank has nonsymmetric band characteristics with respect to the origin, having an individual arbitrary center frequency. Each bandwidth ratio is given by an integer. After band splitting, the signals are decimated and interpolated regularly by a fractional factor to reduce the effects of aliasing at each channel. These filter banks have a one-sided frequency passband. Filters are implemented using complex coefficients. The authors present a synthesis method of two-band and multiband nonuniform filter banks with a fractional decimation. The condition for a perfect reconstruction of the input signal is shown. A simple procedure for designing filter banks is given with examples