Analysis of orthogonal M-band wavelet approximation power

It is focused on the orthogonal M-band wavelet approximation power for band-limited signals and on the quantitative analysis of the approximation behavior of scaling filters and scaling function frequency response near zero. A sharp upper bound of the approximation errors in multiresolution subspaces is obtained for band-limited signals. With this bound one may select better wavelet base and corresponding smaller scale factor to satisfy the given measure of the approximation error. Finally, the experiments of 2-band Daubechies wavelet bases show that signals with the normalized energy and bandwidth almost belong to \%V\-2\% spanned by \%D\%\-8 with the satisfactory error measure.