On transition bandwidth of constrained least-squares filters

Constrained least-squares (LS) filter design combines the features of least-squares and minimax design. In the constrained LS approach, a cutoff frequency is specified whereas the passband edge and stopband edge are left unspecified. This paper presents an empirical formula to quantify the relationship among transition bandwidth, ripple magnitude, and filter order for the class of constrained LS filters. Extensive experiments show good agreement between the predicted and measured data.