DESIGNING QUADRATURE MIRROR FILTER BANKS USING STEEPEST DESCENT METHOD

This paper proposes a new technique for the design of quadrature mirror filter (QMF) banks by exploiting steepest descent method. The design problem is formulated to minimize an objective function, which is a weighted sum of the pass band error and stop band residual energy of the low pass analysis filter of the QMF bank. The minimization has been carried out gradually by respective optimum step lengths in the corresponding steepest descent directions of a linear combination of the objective function and square of the reconstruction error of the QMF bank at the quadrature frequency by optimizing the filter tap weights. The design results show that the proposed method gives a comparable performance to the already existing methods.