US5530959A
Expired / Lapsed
US
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Self-synchronizing scrambler/descrambler without error multiplication
Assignee: Conexant Inc
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Filing: 1994-05-18
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Granted: 1996-06-25
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Expires: 2014-05-18
Abstract
Abstract A self-synchronizing scrambler/descrambler arrangement operates in two modes. In the first, or start-up mode, predetermined data is coupled to the scrambler and transmitted to the descrambler. This data is used to "seed", i.e., load, storage devices in the scrambler and descrambler with the same information. After a predetermined time interval, the start-up mode is terminated, and the scrambler and descrambler each operate in a steady-state mode. In this mode, the information loaded in the scrambler and descrambler devices are used to form the scrambler and descrambler key signals. Advantageously, in the steady-state mode, the occurrence of transmission errors does not effect the contents of the storage devices in the scrambler and descrambler. Hence, the prior art problem of error multiplication is avoided. In applications where a number of coded and multiplexed data channels are communicated over the communications channel linking the scrambler and descrambler, this approach allows the use of a single scrambler/descrambler without degrading the coding benefits.
Inventors
- 👤 Daniel Amrany
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:15
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/02; H04L25/03; H04L25/03828; H04L25/03866
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
129 words
Apparatus comprising means for receiving a scrambled digital signal; and means for descrambling said received digital signal, said descrambling means being operative in first and second time intervals, said descrambling means descrambling said received scrambled signal in said first and second time intervals using a key signal, said descrambling means including means for forming said key signal, said key signal forming means forming said key signal in said first time interval in response to said received scrambled signal in this interval, said key signal forming means being unresponsive to said received scrambled signal in said second time interval; wherein said descrambling means includes a means for controlling that examines an output of said descrambling means and controls the duration of said first time interval in response to this examination.
Claim 2
Dependent Claim
129 words
Apparatus comprising means for receiving a scrambled digital signal; and means for descrambling said received digital signal, said descrambling means being operative in first and second time intervals, said descrambling means descrambling said received scrambled signal in said first and second time intervals using a key signal, said descrambling means including means for forming said key signal, said key signal forming means forming said key signal in said first time interval in response to said received scrambled signal in this interval, said key signal forming means being unresponsive to said received scrambled signal in said second time interval; wherein said descrambling means includes a means for controlling that examines an output of said descrambling means and controls the duration of said first time interval in response to this examination.
Claim 3
Dependent Claim
28 words
The apparatus of claim 1 wherein said key signal forming means during said second time interval is responsive to said key signal formed during said first time interval.
Claim 4
Dependent Claim
20 words
The apparatus of claim 1 wherein the examination provided by said examining means compares said output to a reference signal.
Claim 5
Dependent Claim
145 words
Apparatus comprising means for receiving a scrambled digital signal; and means for descrambling said received digital signal, said descrambling means being operative in first and second time intervals, said descrambling means descrambling said received scrambled signal in said first and second time intervals using a key signal, said descrambling means including means for forming said key signal, said key signal forming means forming said key signal in said first time interval in response to said received scrambled signal in this interval, said key signal forming means being unresponsive to said received scrambled signal in said second time interval wherein said descrambling means includes a means for controlling that examines an output of said descrambling means and controls the duration of said first time interval in response to this examination wherein said key signal forming means combines values of said received scrambled signal at different times.
Claim 6
Dependent Claim
145 words
Apparatus comprising means for receiving a scrambled digital signal; and means for descrambling said received digital signal, said descrambling means being operative in first and second time intervals, said descrambling means descrambling said received scrambled signal in said first and second time intervals using a key signal, said descrambling means including means for forming said key signal, said key signal forming means forming said key signal in said first time interval in response to said received scrambled signal in this interval, said key signal forming means being unresponsive to said received scrambled signal in said second time interval wherein said descrambling means includes a means for controlling that examines an output of said descrambling means and controls the duration of said first time interval in response to this examination wherein said key signal forming means combines values of said received scrambled signal at different times.
Claim 7
Dependent Claim
35 words
The apparatus of claim 4 wherein said key signal forming means during said first time interval combines the values of said received scrambled signal at a plurality of different times during this first time interval.
Claim 8
Dependent Claim
31 words
The apparatus of claim 4 wherein said key signal forming means during said second time interval combines the values of said key signal at different times within said first time interval.
Claim 9
Dependent Claim
153 words
Apparatus comprising means for receiving a scrambled digital signal: and means for descrambling said received digital signal, said descrambling means being operative in first and second time intervals, said descrambling means descrambling said received scrambled signal in said first and second time intervals using a key signal, said descrambling means including means for forming said key signal, said key signal forming means forming said key signal in said first time interval in response to said received scrambled signal in this interval, said key signal forming means being unresponsive to said received scrambled signal in said second time interval wherein said descrambling means includes a means for controlling that examines an output of said descrambling means and controls the duration of said first time interval in response to this examination wherein said descrambling means key signal forming means includes means for storing prior values of said received scrambled signal at a plurality of times.
Claim 10
Dependent Claim
153 words
Apparatus comprising means for receiving a scrambled digital signal: and means for descrambling said received digital signal, said descrambling means being operative in first and second time intervals, said descrambling means descrambling said received scrambled signal in said first and second time intervals using a key signal, said descrambling means including means for forming said key signal, said key signal forming means forming said key signal in said first time interval in response to said received scrambled signal in this interval, said key signal forming means being unresponsive to said received scrambled signal in said second time interval wherein said descrambling means includes a means for controlling that examines an output of said descrambling means and controls the duration of said first time interval in response to this examination wherein said descrambling means key signal forming means includes means for storing prior values of said received scrambled signal at a plurality of times.
Claim 11
Dependent Claim
34 words
The apparatus of claim 1 wherein said received scrambled signal is a multiplexed one and descrambling means provides a multiplexed output signal, and said apparatus further includes means for demultiplexing said multiplexed output signal.
Claim 12
Dependent Claim
31 words
The apparatus of claim 8 wherein the multiplexed received scrambled signal includes coded signals and said apparatus further includes at least one decoder coupled to an output of said demultiplexing means.
Claim 13
Dependent Claim
33 words
The apparatus of claim 9 wherein the coded signal includes at least one coded interleaved signal and said apparatus further includes at least one deinterleaver coupled to an output of said demultiplexing means.
Claim 14
Dependent Claim
130 words
Apparatus comprising means for receiving a digital data signal; and means for scrambling said received digital data signal, said scrambling means being operative in first and second time intervals, said scrambling means scrambling said received digital data signal in said first and second time intervals using a key signal, said scrambling means including means for forming said key signal in said first and second time intervals, in said first time interval said forming means being responsive to the scrambled digital data signals in said first time interval and, in said second time interval, said forming means being unresponsive to said scrambled digital data signal in said second time interval; wherein said scrambling means includes means for storing prior values of said scrambled digital data signal at a plurality of times.
Claim 15
Dependent Claim
130 words
Apparatus comprising means for receiving a digital data signal; and means for scrambling said received digital data signal, said scrambling means being operative in first and second time intervals, said scrambling means scrambling said received digital data signal in said first and second time intervals using a key signal, said scrambling means including means for forming said key signal in said first and second time intervals, in said first time interval said forming means being responsive to the scrambled digital data signals in said first time interval and, in said second time interval, said forming means being unresponsive to said scrambled digital data signal in said second time interval; wherein said scrambling means includes means for storing prior values of said scrambled digital data signal at a plurality of times.
Claim 16
Dependent Claim
149 words
Apparatus comprising means for receiving a digital data signal; and means for scrambling said received digital data signal, said scrambling means being operative in first and second time intervals, said scrambling means scrambling said received digital data signal in said first and second time intervals using a key signal, said scrambling means including means for forming said key signal in said first and second time intervals, in said first time interval said forming means being responsive to the scrambled digital data signals in said first time interval and, in said second time interval, said forming means being unresponsive to said scrambled digital data signal in said second time interval wherein said scrambling means includes means for storing prior values of said scrambled digital data signal at a plurality of times, wherein said scrambling means forms said key signal by combining values of said received scrambled signal at different times.
Claim 17
Dependent Claim
149 words
Apparatus comprising means for receiving a digital data signal; and means for scrambling said received digital data signal, said scrambling means being operative in first and second time intervals, said scrambling means scrambling said received digital data signal in said first and second time intervals using a key signal, said scrambling means including means for forming said key signal in said first and second time intervals, in said first time interval said forming means being responsive to the scrambled digital data signals in said first time interval and, in said second time interval, said forming means being unresponsive to said scrambled digital data signal in said second time interval wherein said scrambling means includes means for storing prior values of said scrambled digital data signal at a plurality of times, wherein said scrambling means forms said key signal by combining values of said received scrambled signal at different times.
Claim 18
Dependent Claim
162 words
Apparatus comprising means for receiving a digital data signal; and means for scrambling said received digital data signal, said scrambling means being operative in first and second time intervals, said scrambling means scrambling said received digital data signal in said first and second time intervals using a key signal, said scrambling means including means for forming said key signal in said first and second time intervals, in said first time interval said forming means being responsive to the scrambled digital data signals in said first time interval and, in said second time interval, said forming means being unresponsive to said scrambled digital data signal in said second time interval wherein said scrambling means includes means for storing prior values of said scrambled digital data signal at a plurality of times, wherein said scrambling means forms said key signal during said first time interval by combining values of said scrambled digital data signal at a plurality of times during this first time interval.
Claim 19
Dependent Claim
162 words
Apparatus comprising means for receiving a digital data signal; and means for scrambling said received digital data signal, said scrambling means being operative in first and second time intervals, said scrambling means scrambling said received digital data signal in said first and second time intervals using a key signal, said scrambling means including means for forming said key signal in said first and second time intervals, in said first time interval said forming means being responsive to the scrambled digital data signals in said first time interval and, in said second time interval, said forming means being unresponsive to said scrambled digital data signal in said second time interval wherein said scrambling means includes means for storing prior values of said scrambled digital data signal at a plurality of times, wherein said scrambling means forms said key signal during said first time interval by combining values of said scrambled digital data signal at a plurality of times during this first time interval.
Claim 20
Dependent Claim
161 words
Apparatus comprising means for receiving a digital data signal; and means for scrambling said received digital data signal, said scrambling means being operative in first and second time intervals, said scrambling means scrambling said received digital data signal in said first and second time intervals using a key signal, said scrambling means including means for forming said key signal in said first and second time intervals, in said first time interval said forming means being responsive to the scrambled digital dater signals in said first time interval and, in said second time interval, said forming means being unresponsive to said scrambled digital data signal in said second time interval wherein said scrambling means includes means for storing prior values of said scrambled digital data signal at a plurality of times, wherein said scrambling means forms said key signal during said second time interval by combining values of said key signal formed at a plurality of times within said first time interval.
Claim 21
Dependent Claim
161 words
Apparatus comprising means for receiving a digital data signal; and means for scrambling said received digital data signal, said scrambling means being operative in first and second time intervals, said scrambling means scrambling said received digital data signal in said first and second time intervals using a key signal, said scrambling means including means for forming said key signal in said first and second time intervals, in said first time interval said forming means being responsive to the scrambled digital dater signals in said first time interval and, in said second time interval, said forming means being unresponsive to said scrambled digital data signal in said second time interval wherein said scrambling means includes means for storing prior values of said scrambled digital data signal at a plurality of times, wherein said scrambling means forms said key signal during said second time interval by combining values of said key signal formed at a plurality of times within said first time interval.
Claim 22
Dependent Claim
29 words
The apparatus of claim 11 wherein said received digital data signal is a multiplexed one and apparatus includes multiplexing means serially connected to an input of said scrambling means.
Claim 23
Dependent Claim
32 words
The apparatus of claim 15 wherein the multiplexed received digital data signal includes coded signals and said apparatus further includes at least one coder connected to an input of said multiplexing means.
Claim 24
Dependent Claim
33 words
The apparatus of claim 16 wherein the coded signal includes at least one coded interleaved signal and said apparatus further includes at least one interleaver coupled to an input of said multiplexing means.
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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) | 1999-06-25 | 1999-12-25 | 2000-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-06-25 | 2003-12-25 | 2004-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-06-25 | 2007-12-25 | 2008-06-25 | $7700.00 | Window Closed / Lapsed |