Modulated filter banks with minimum output distortion in presence of subband quantization

This paper presents modulated minimum mean squared error (MMSE) filter banks, designed for subband coding purposes. Uniform scalar quantizers, the synthesis prototype and an additional gain control factor per subband are optimized in a rate-distortion sense. The main advantage of the proposed solution is to keep the efficient modulated implementation of the synthesis filter bank, while reducing the reconstruction distortion introduced by quantization of the subband signals. It is shown that, in many circumstances, the resulting schemes are almost as efficient as plain MMSE filter banks (Wiener filters with optimized quantizers).