Multichannel decimation/interpolation filter
AssigneeHewlett-Packard Company
InventorDouglas W. Morton
Life of this patent
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Abstract
A multichannel, digital filter capable of operation in either decimation or interpolation mode receives sequences of time multiplexed sampled from M input channels and filters the input values from each channel to produce filtered output data for each channel. The filter includes N serially connected digital low pass filters for each channel. Low pass filter N+1 is executed only half as often as low pass filter N, thereby providing a decimation or interpolation function, depending on which mode is selected. The filter may include apparatus for sequencing the low pass filters and for storing the state variables employed by such filters. In decimation mode, the filter may either operate in a single or multipass mode.
Claims5
An apparatus comprising:
- input means for providing an input digital signal, and input digital signal being comprised of a plurality of samples provided at a first rate;
- signal processing means having an input coupled to the input means for processing the samples comprising the input digital signal and for producing a first output signal, said processing means including means for processing signal samples at a second rate greater than the first, said second rate defining a characteristic processing interval for processing a single signal sample, the difference between the second and first rates leaving unused processing intervals during which the processing means is not processing samples to the input digital signal, said signal processing means processing samples of the first output signal during certain of said unused processing intervals.
Dependencies are inferred from the claim text.