On the performance analysis of the subband adaptive digital filter
A performance analysis of the subband adaptive digital filter (SBADF) is presented, and some examples are given which show that SBADF yields better convergence properties than the full band adaptive digital filter (FBADF). The optimum filter in the subband and the relationship between the transfer function of the SBADF and that of the FBADF after convergence are derived. The error surface of the SBADF is derived and compared with that of the FBADF. The autocorrelation functions of signals in the subband are derived, from which the convergence behavior of the filter coefficients and mean square error can be examined. Computer simulation results show that the analysis presented is in close agreement with the experiment. It is shown that the SBADF provides better convergence properties than the FBADF in the case of adaptive line enhancer (ALE) and adaptive channel equalizer for severely distorted channels.<<ETX>>