Title :
Finite wordlength effects in quadrature mirror filter banks
Author :
Schusdziarra, M. ; Fliege, N.J. ; Zölzer, U.
Author_Institution :
Tech. Univ. of Hamburg, Germany
Abstract :
The authors investigate the effects of finite wordlength on the performance of QMF (quadrature mirror filter) banks implemented with fixed-point arithmetic. A statistical model for roundoff errors is used to predict the output roundoff noise in each subband. The amplitudes of the parasitic oscillations which are due to a DC component in each subband are predicted with the same model. For two´s complement arithmetic, the authors discuss the effects of truncation and rounding, and present analysis results. A general framework for analyzing different splitting schemes is given. The enhancement of roundoff noise for low frequencies is obvious. It is pointed out that parasitic frequency components can be avoided if two´s complement rounding is used, while roundoff noise can only be reduced by increasing the wordlength
Keywords :
digital arithmetic; filtering and prediction theory; random noise; roundoff errors; statistical analysis; DC component; QMF; finite wordlength; fixed-point arithmetic; output roundoff noise; parasitic oscillations; quadrature mirror filter banks; rounding; roundoff errors; splitting schemes; statistical model; truncation; two´s complement arithmetic; Arithmetic; Channel bank filters; Filter bank; Finite impulse response filter; Finite wordlength effects; Frequency; Mirrors; Predictive models; Quantization; Signal synthesis;
Conference_Titel :
Circuits and Systems, 1992. ISCAS '92. Proceedings., 1992 IEEE International Symposium on
Conference_Location :
San Diego, CA
Print_ISBN :
0-7803-0593-0
DOI :
10.1109/ISCAS.1992.230256
