A quadratic-constrained least-squares approach to the design of digital filter banks

The author formulates the filter bank design problem as a quadratic-constrained least-square minimization problem. The solution of the minimization problem converges very fast since the cost function and the constraints are quadratic functions with respect to the unknown parameters. The cosine-modulated and the two-channel linear-phase filter banks are designed using the proposed formulation. Compared to other design methods, the proposed technique yields PR (perfect reconstruction) filter banks with much higher stopband attenuation. The filter designed using the new approximation could be used as an initialization filter in a conventional PR filter bank design