Facility for reducing a data rate
OwnerAndreas Menkhoffinventor
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Abstract
A facility for reducing the data rate of a data sequence (d1) is provided, including a switchable filter device (1) which delivers first output values (dn) after a sampling intervals in a first state and second output values (dm) after a +1 sampling intervals in a second state, and which has at least one tracking data window (dw) of different sizes (dwf1, dwf2) for forming filtered data values (df'). A control device (10) causes n first output values (dn) and m second output values (dm) to be formed within equally long time periods (I2) of the data sequence (d1), with the number of n first and m second output values being determined by a rule r=a+m/(n+m), where r is a desired data rate reduction factor.
Claims20
A device for reducing the data rate of a data sequence (d1), comprising:
- a switchable filter device (1) which delivers first output values (dn) after a sampling intervals in a first state and second output values (dm) after a+1 sampling intervals in a second state, and has at least one tracking data window (dw;
- dw1, dw2) for forming filtered data values (df';
- df', df"), wherein
- if only one tracking data window (dw) is present, this data window (dw) is assigned at least two different window sizes (dwf1, dwf2) whose selection is dependent on the sequence of the first (dn) and second output values (dm), and,
- if more than one tracking data window (dw1, dw2) are present, these are assigned at least two different window sizes (dwf1, dwf2), and the selection of the respective data window (dw1, dw2) with the associated window size is dependent on the sequence of the first (dn) and second output values (dm), and
- one (dwf1) of the window sizes (dwf1, dwf2) comprises b samples, and the other (dwf2) c samples, with b.gtoreq.a and c.gtoreq.a+1;
- and
- a control device (10) which is coupled to the switchable filter device (1) and, by means of the first and second states, causes the formation of n first output values (dn) and m second output values (dm) as well as the selection of the associated window sizes (dwf1, dwf2) or data windows (dw1, dw2) within equally long time periods (I2) of the data sequence d1, the number of n first (dn) and m second output values (dm) being determined by a rule r=a+m/(n+m), where r is a data rate reduction factor.
A device for reducing the input data rate of an input data sequence comprising:
- a first clock means for providing a first clock signal dependent upon said input data rate;
- an accumulator coupled to said first clock means for receiving said input data sequence;
- a decimation switch coupled to said accumulator for transferring data derived from said input data sequence;
- a differentiator coupled to said decimation switch for receiving said transferred data;
- and,
- a buffer coupled to said differentiator and to a second clock means, said second clock means providing a second clock signal dependent upon said reduced data rate, said buffer for receiving a time averaged data sequence associated with said input data sequence from said differentiator and for providing said time averaged data sequence at said reduced data rate.
A method for converting an input data sequence having an input data rate to a corresponding output data sequence at a different output data rate comprising:
- in a first mode, averaging said input data sequence over a first time interval to determine an output data sequence value corresponding to said first mode;
- in a second mode, averaging said input data sequence over a second time interval to determine an output data sequence value corresponding to said second mode;
- and,
- selectively outputting said output data sequence values corresponding to said first and second modes at said second data rate to form said output data sequence;
- wherein the duration of said second time interval is dependent upon the duration of said first time interval and the ratio of said input data rate to said output data rate, and,
- wherein the ratio of said output data sequence values output from said first mode to said output data sequence values output from said second mode is dependent upon said first and second interval durations and said ratio of said input data rate to said output data rate.
Dependencies are inferred from the claim text.