Multichannel decimation/interpolation filter
AssigneeHewlett-Packard Company
InventorDouglas W. Morton
Life of this patent
Estimating the term…
Abstract
A multichannel, digital filter capable of operation in either decimination 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.
Claims15
A digital, multichannel filter, comprising:
- means for receiving digital channel input data comprising a sequence of time multiplexed samples from M channels, M being greater than one;
- and
- digital filter means for low pass filtering the channel input data from each channel to produce channel output data for each channel, said digital filter means further comprising N digital low pass filters for each channel, the low pass filters for each channel being numbered and ordered from 1 through N such that low pass filters n and n +1 are serially connected for all n from 1 to N-1, each low pass filter comprising a plurality of state variables, the filter further including means for receiving pass input data and means for producing pass output data.
A digital, multichannel filter, comprising:
- means for receiving digital channel input data comprising a sequence of time multiplexed samples from M channels, M being greater than one;
- and
- digital filter means for low pass filtering the channel input data from each channel to produce channel output data for each channel, said digital filter means further comprising a decimation filter including N1 digital low pass filters for each channel and means for receiving and storing data representing an output pass number N, each low pass filter comprising a plurality of state variables, means for receiving pass input data, and means for producing pass output data, the low pass filters for each channel being numbered and ordered from 1 through N1 such that low pass filter 1 receives a portion of the channel input data for the associated channel as pass input data, such that a portion of the pass output data produced by low pass filter n for a given channel is provided as pass input data to low pass filter n+1 for the same channel, where n is greater than zero and less than N1, and such that the channel output data for each channel comprises the pass output data of low pass filter N for that channel.
Dependencies are inferred from the claim text.