A time discrete filter comprises a sampling rate converter provided with
an input and an output, and a down-sampler having a down-sampling factor
nd. The time discrete filter further comprises an up-sampler having an
up-sampling factor nu, whereby the up-sampler is coupled to the converter
input, and the converter output is coupled to the down-sampler. It has
been found that if a sampling rate conversion operation is preceded by an
up-sampling operation and only after the conversion is followed by a
down-sampling operation to a wanted sampling frequency, that then the
complexity in terms of the ultimate number of calculations, in particular
multiplications and additions, is reduced. This leads to a decrease of
the number of instructions per second which is a measure for the
complexity of a Digital Signal Processing (DSP) algorithm. In addition
this leads to an associated decrease of power consumed by a DSP, such as
applied in for example audio, video, and (tele)communication devices, as
well as radio and television apparatus.