Design of M-Band NPR Cosine-Modulated Filterbank Using IFIR Technique

This paper presents a design of M-band near perfect reconstructed (NPR) cosine-modulated filterbank (CMFB). The prototype filter is formulated as an interpolated finite impulse response (IFIR) filter. Suitable stretched factor is used to provide considerable reduction in computation cost as well as minimum value of error parameters. Further minimization in errors has been achieved by applying a linear gradient optimization technique. The IFIR approach provides reduction in stopband energy as side-lobe-fall-off-rate (SLFOR) in magnitude response of the prototype filter is improved. Design examples have been included to illustrate the effectiveness of the proposed technique over the existing work.