US5023825A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coefficient reduction in a low ratio sampling rate converter
Assignee: Tektronix Inc
•
Filing: 1990-08-20
•
Granted: 1991-06-11
•
Expires: 2010-08-20
Abstract
Abstract A technique for reducing the number of coefficients in a low ratio sampling rate converter divides each input sampling rate interval into a plurality of bins. For each bin a set of conversion coefficients is computed. So long as output data samples lie within the same bin, the same set of coefficients is applied. When the output data samples move to another bin, the set of coefficients applied is changed. Thus a finite set of coefficients are computed rather than computing an exact set for each output data sample.
Inventors
- 👤 Ajay K. Luthra
- 👤 Ganesh Rajan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:21
CPC Classifications
H; H03; H03H; H03H17/00; H03H17/02; H03H17/0223; H03H17/0227; H03H17/06; H03H17/0621; H03H17/0635; H03H17/065; H03H17/0664; H03H17/0685; H04; H04N; H04N5/00; H04N5/14; H04N7/00; H04N7/01; H04N7/0135
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
140 words
A method of converting an input signal sampled at a first rate to an output signal sampled at a second rate, the ratio between the rates being close to one, comprising the steps of: dividing each sampling interval for the input signal into a finite number of bins; calculating a set of filter coefficients for each bin; storing the samples of the input signal in a buffer at the first rate; reading out the samples of the input signal from the buffer at the second rate; and applying the sets of filter coefficients to the samples read out of the buffer according to within which one of the bins the samples fall, the number of sets of filter coefficients being substantially less than the number of samples output per sampling interval of the input signal, to produce the output signal.
Claim 2
Independent Claim
140 words
A method of converting an input signal sampled at a first rate to an output signal sampled at a second rate, the ratio between the rates being close to one, comprising the steps of: dividing each sampling interval for the input signal into a finite number of bins; calculating a set of filter coefficients for each bin; storing the samples of the input signal in a buffer at the first rate; reading out the samples of the input signal from the buffer at the second rate; and applying the sets of filter coefficients to the samples read out of the buffer according to within which one of the bins the samples fall, the number of sets of filter coefficients being substantially less than the number of samples output per sampling interval of the input signal, to produce the output signal.
Claim 3
Independent Claim
162 words
An apparatus for converting an input signal sampled at a first rate to an output signal sampled at a second rate, the ratio between the rates being close to one, comprising: means for calculating a plurality of sets of filter coefficients, each set of filter coefficients corresponding to one of a plurality of bins into which each sampling interval for the input signal is divided; means for storing samples of the input signal, the samples being input to the storing means at the first rate and being read out from the storing means at the second rate; and means for applying the sets of filter coefficients to the samples read out from the storing means, the set of filter coefficients applied to each sample being determined by the bin into which the sample falls, the number of sets of filter coefficients being substantially less than the number of samples output per sampling interval of the input signal, to produce the output signal.
Claim 4
Independent Claim
162 words
An apparatus for converting an input signal sampled at a first rate to an output signal sampled at a second rate, the ratio between the rates being close to one, comprising: means for calculating a plurality of sets of filter coefficients, each set of filter coefficients corresponding to one of a plurality of bins into which each sampling interval for the input signal is divided; means for storing samples of the input signal, the samples being input to the storing means at the first rate and being read out from the storing means at the second rate; and means for applying the sets of filter coefficients to the samples read out from the storing means, the set of filter coefficients applied to each sample being determined by the bin into which the sample falls, the number of sets of filter coefficients being substantially less than the number of samples output per sampling interval of the input signal, to produce the output signal.
References Cited (Backward Citations)
US3997773A
Cited
US4472785A
Cited
US4584659A
Cited
US4881191A
Cited
US4837619A
Cited
US4866647A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-06-10 | 1994-12-10 | 1995-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-10 | 1998-12-10 | 1999-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-10 | 2002-12-10 | 2003-06-11 | $7700.00 | Window Closed / Lapsed |