US4752953A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital audio scrambling system with pulse amplitude modulation
Assignee: Arris Technology Inc
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Filing: 1986-08-11
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Granted: 1988-06-21
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Expires: 2006-08-11
Abstract
Abstract In a system for scrambling an audio signal for transmission with a video signal having non-video information intervals, an analog audio signal is converted into a scrambled compressed digital audio signal; individual bits from the scrambled compressed digital audio signal are combined to provide 2-bit digital words; each digital word is converted into an 8-bit digital PAM data signal having a binary value bearing a predetermined relationship to the binary value of the converted 2-bit digital word; the 8-bit digital PAM data signal is converted into a 4-level PAM analog signal; and the PAM analog signals are inserted into the non-video information intervals of the video signal for transmission. A descrambling system descrambles the 4-level PAM analog signals by a complementary scheme.
Inventors
- 👤 Woo H. Paik
- 👤 Jerrold A. Heller
- 👤 Gordon K. Walker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:21
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/79; H04N9/80; H04N9/802; G; G11; G11B; G11B20/00; G11B20/10; G11B20/10527; G11B20/18; G11B20/1806; G11B20/1809; H04K; H04K1/00; H04K1/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
124 words
A system for scrambling an audio signal for transmission with a video signal having non-video information intervals comprising means for converting an analog audio signal into a scrambled compressed digital audio signal; means for combining individual bits from the scrambled compressed digital audio signal to provide n-bit digital words where n is at least equal to two; means for converting each digital word into a >n-bit digital PAM data signal having a binary value bearing a predetermined relationship to the binary value of the converted n-bit digital word: means for converting the >n-bit digital PAM data signal into an 2 n -level PAM analog signal; and means for inserting the PAM analog signals into the non-video information intervals of the video signal for transmission.
Claim 2
Independent Claim
124 words
A system for scrambling an audio signal for transmission with a video signal having non-video information intervals comprising means for converting an analog audio signal into a scrambled compressed digital audio signal; means for combining individual bits from the scrambled compressed digital audio signal to provide n-bit digital words where n is at least equal to two; means for converting each digital word into a >n-bit digital PAM data signal having a binary value bearing a predetermined relationship to the binary value of the converted n-bit digital word: means for converting the >n-bit digital PAM data signal into an 2 n -level PAM analog signal; and means for inserting the PAM analog signals into the non-video information intervals of the video signal for transmission.
Claim 3
Dependent Claim
20 words
A system according to claim 1, wherein n equals two, and the digital PAM data signal consists of eight bits.
Claim 4
Independent Claim
195 words
A system for descrambling a scrambled audio signal derived by converting an analog audio signal into a digital signal to provide a scrambled compressed digital audio signal, by combining individual bits from the scrambled compressed digital audio signal to provide n-bit digital words where n is at least equal to two by converting each digital word into a >n-bit digital PAM data signal having a binary value bearing a predetermined relationship to the binary value of the converted n-bit digital word, and by converting the >n-bit digital PAM data signal into a 2 n -level PAM analog signal, wherein the PAM analog signals were inserted into non-video information intervals of a video signal for transmission, the system comprising means for converting the 2 n -level PAM analog signals into >n-bit digital PAM data signals; means for converting each >n-bit digital PAM data signal into an n-bit digital word having a value bearing a predetermined relationship to the binary value of the >n-bit digital PAM data signal; means for providing a scrambled digital audio signal from the n-bit digital words; and means for converting the scrambled digital audio signal into a descrambled decompressed analog audio signal.
Claim 5
Independent Claim
195 words
A system for descrambling a scrambled audio signal derived by converting an analog audio signal into a digital signal to provide a scrambled compressed digital audio signal, by combining individual bits from the scrambled compressed digital audio signal to provide n-bit digital words where n is at least equal to two by converting each digital word into a >n-bit digital PAM data signal having a binary value bearing a predetermined relationship to the binary value of the converted n-bit digital word, and by converting the >n-bit digital PAM data signal into a 2 n -level PAM analog signal, wherein the PAM analog signals were inserted into non-video information intervals of a video signal for transmission, the system comprising means for converting the 2 n -level PAM analog signals into >n-bit digital PAM data signals; means for converting each >n-bit digital PAM data signal into an n-bit digital word having a value bearing a predetermined relationship to the binary value of the >n-bit digital PAM data signal; means for providing a scrambled digital audio signal from the n-bit digital words; and means for converting the scrambled digital audio signal into a descrambled decompressed analog audio signal.
Claim 6
Dependent Claim
20 words
A system according to claim 3, wherein n equals two, and the digital PAM data signal consists of eight bits.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-21 | 1991-12-21 | 1992-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-21 | 1995-12-21 | 1996-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-21 | 1999-12-21 | 2000-06-21 | $7700.00 | Window Closed / Lapsed |