Phase Factor Influence on Amplitude Distortion and Aliasing of Pseudo-QMF Banks
نویسندگان
چکیده
The spectral factorization approach to pseudo-QMF design doesn't involve any optimization in order to obtain the prototype filter used in the cosine modulation. In this paper, the initial phase factor influence on amplitude distortion is analyzed and a new expression to design pseudo-QMF bank without restriction on the filter's length is proposed. This filter bank introduces a very small aliasing error at the output when the prototype filter has high stopband attenuation and, when the initial phase factor is appropriately chosen, the amplitude distortion, and therefore the total error on the reconstructed signal, are also reduced. Several examples are included. Key-Words: Spectral factorization approach, phase factor, amplitude distortion, aliasing
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