Efficient Prototype Filter Realizations for Cosine-Modulated Filter Banks

This paper presents efficient realizations of prototype filters for biorthogonal cosine-modulated filter banks with arbitrary overall system delay. The implementation is based on lifting schemes. The lifting coefficients will be approximated such that the filter operations can be realized by a few shift and add operations. Since the lifting scheme is robust against coefficient quantization we do not loose the perfect reconstruction (PR) property of the filter bank when doing this approximation. The original and the approximated prototype filters are compared in terms of complexity and stopband attenuation.