Patent ID: 6760379
Filing Date: 2004-07-06
Classification: H03H

Abstract:
A filtering process for achieving a transparent cascade on up conversion in the sampling rate ratio N:M where N and M are integers and subsequent M:N down conversion, where the up and down conversion ratios N:M and M:N respectively are rational numbers and the integers N and M satisfy the condition 1input and is chosen to take the form Sup(n)=&Sgr;Sinput(k).g(Nnâˆ’Mk) where k is the running integer over which the sum is taken and wherein a corresponding down conversion filter operates on the up converted signal Sup and is chosen to take the form Sdowm(n)=&Sgr;Sup(k).h(Mnâˆ’Nk); the pair (g, h) of up and down conversion filters being chosen so that &Sgr;h(Mnâˆ’Nk).g(Nkâˆ’Mm) is equal to unity if n=m and is otherwise equal to zero.