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US5274372A Expired / Lapsed US ⏱️ 0.0 years remaining

Sampling rate conversion using polyphase filters with interpolation

Assignee: Grass Valley Group Inc
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Filing: 1992-10-23
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Granted: 1993-12-28
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Expires: 2012-10-23
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Abstract

Abstract A sampling rate converter for converting an input digital signal, such as D2 PAL, into an output digital signal, such as D1 PAL, has a pair of polyphase filters. The input digital signal is input in parallel to the two polyphase filters, with the phase selected by one of the filters being offset by one from that of the other. The outputs of the polyphase filters are input to a linear interpolator to produce the output digital signal. The resolution of the sampling rate conversion is a function of the number of phases N of the polyphase filters and the number of interpolation steps M of the interpolator.

Inventors

  • 👤 Ajay K. Luthra
  • 👤 Ganesh Rajan
  • 👤 Ronald Alspaugh

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 05:17
CPC Classifications
H; H03; H03H; H03H17/00; H03H17/02; H03H17/06; H03H17/0621; H03H17/0635; H03H17/0685; H03H17/0248; H03H17/0264; H03H17/0273; H03H17/0275; H04; H04N; H04N7/00; H04N7/01; H04N7/0102; H03H17/0223; H03H2017/0247

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 72 words
An apparatus for converting a digital signal from an input sampling rate to an output sampling rate comprising: a pair of polyphase filters, each having the digital signal at the input sampling rate as an input, with the phase selection of one polyphase filter being offset by one from the other; and means for interpolating between the outputs of the polyphase filters to produce the digital signal at the output sampling rate.
Claim 2
Independent Claim 72 words
An apparatus for converting a digital signal from an input sampling rate to an output sampling rate comprising: a pair of polyphase filters, each having the digital signal at the input sampling rate as an input, with the phase selection of one polyphase filter being offset by one from the other; and means for interpolating between the outputs of the polyphase filters to produce the digital signal at the output sampling rate.
Claim 3
Dependent Claim 33 words
The apparatus as recited in claim 1 further comprising means for decimating the output of the interpolating means to reduce the number of samples in the digital signal at the output sampling rate.

References Cited (Backward Citations)

US4954824A Cited
US5204827A Cited
US5128760A Cited
US5182633A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-12-27 1997-06-28 1997-12-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-12-27 2001-06-28 2001-12-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-12-27 2005-06-28 2005-12-28 $7700.00 Window Closed / Lapsed

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