A Simple Method to Design FIR QMF Banks

An iterative method for the design of two-band quadrature mirror filter (QMF) banks proposed by Cruesere and Mitra is examined and improved by designing the prototype filters using window method instead of equiripple method. The Kaiser window and Chebyshev window functions are used in the design of prototype filters. The cut-off frequency has been adjusted in this improved method instead of passband frequency which is the case in Cruesere and Mitra algorithm. The paper concludes with design results and comparisons that show that our new improved method takes less computational effort when compared with Cruesere and Mitra method.