Frequency sampling design of prototype filters for nearly perfect reconstruction cosine-modulated filter banks

A new approach to the design of prototype filters for conventional nearly perfect reconstruction (N-PR) cosine-modulated filter banks is presented. The new method is based on the frequency sampling approach for the design of finite-impulse response filters. In the proposed approach, the magnitude response values of samples in the transition band of the prototype filter are the only parameters to be optimized. The analytical and simulation results show that despite there being no direct control over the stopband attenuation of the prototype filter, the performance of the filter bank is extremely good, and in several cases, the whole system closely satisfies the PR property.