Low-delay filtering

摘要

A method of frequency-domain filtering is provided that includes a plurality of filters, the plurality of filters including at least one constrained filter(s) W=I, I and at least one unconstrained filter(s) W=1,K− The method includes cascading the W k=i,K unconstrained filter(s). A single constraint window C is applied to the cascaded W=i,K unconstrained filter(s). The W=1,I constrained filter(s) are cascaded with the constrained cascaded Wk=1,K unconstrained filter(s) to form a resulting filter Wll=C(W 1{circle around (x)} . . . {circle around (x)} W){circle around (x)} W . . . W. The frequency domain representation of the single constraint window C may be based, at least in part, on a time domain representation of a single constraint window C that has been circularly shifted such that the frequency domain representation of the constraint window matches a property of the frequency domain representation of the cascaded W=1,K unconstrained filters.

主权项

1. A method of adaptive digital filtering, the method comprising:
determining a time domain representation of a soft constraint window, the soft constraint window for zero padding an adaptive digital filter; circularly shifting the time domain representation of the soft constraint matrix to align in the frequency domain with the adaptive digital filter; transforming the time domain representation of the circularly shifted soft constraint matrix to a frequency domain representation of the circularly shifted soft constraint matrix; determining a frequency domain representation of the adaptive digital filter; applying the frequency domain representation of the circularly shifted soft constraint matrix window to the frequency domain representation of the adaptive digital filter, such that the resulting adaptive digital filter corresponds to a digital filter in the time domain that includes a plurality of consecutive zeros.