US4839724A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the digital transmission of information
Assignee: Deutsche AG fuer Unterhaltungselectronic OHG
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Filing: 1987-02-07
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Granted: 1989-06-13
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Expires: 2007-02-07
Abstract
Abstract A process for the digital transmission of video signals, wherein the signals to be transmitted are coded according to a variable codeword length code, and this code is adapted at time intervals, preferably at regular time intervals, to a statistic of the signals transmitted.
Inventors
- 👤 Heinz-Werner Keesen
- 👤 Hartmut Peters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:27
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/32; H03; H03M; H03M7/00; H03M7/30; H03M7/40; H03M7/42; H04J; H04J3/00; H04L5/00; H04L5/22; H04N; H04N19/00; H04N19/10; H04N19/134; H04N19/146; H04N19/152; H04N19/50; H04N19/593
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
155 words
In a method of transmitting digital data, including processing digital data as groups of values in a source coder, encoding the values of the groups in a variable codeword length encoder according to a defined variable codeword length code to provide signals corresponding to the values of the groups, feeding the signals corresponding to the values of the groups to a channel coder and then to a transmission channel, and finally feeding the signals corresponding to the values from the transmission channel through a channel decoder and a variable codeword length decoder to a source decoder, the improvement comprising: adapting the defined variable codeword length code to a statistical frequency of the occurrence of the values of the groups being transmitted at desired time intervals; and transmitting at least the changes in the adapted variable codeword length code via the channel coder, the transmission channel and the channel decoder to the variable codeword length encoder.
Claim 2
Dependent Claim
155 words
In a method of transmitting digital data, including processing digital data as groups of values in a source coder, encoding the values of the groups in a variable codeword length encoder according to a defined variable codeword length code to provide signals corresponding to the values of the groups, feeding the signals corresponding to the values of the groups to a channel coder and then to a transmission channel, and finally feeding the signals corresponding to the values from the transmission channel through a channel decoder and a variable codeword length decoder to a source decoder, the improvement comprising: adapting the defined variable codeword length code to a statistical frequency of the occurrence of the values of the groups being transmitted at desired time intervals; and transmitting at least the changes in the adapted variable codeword length code via the channel coder, the transmission channel and the channel decoder to the variable codeword length encoder.
Claim 3
Dependent Claim
51 words
The method defined in claim 1 wherein: each of the variable codeword length encoder and decoder includes a RAM in which the variable codeword length code is stored; and said step of encoding the values includes providing the corresponding addresses in the RAM to provide the signals corresponding to the values.
Claim 4
Dependent Claim
18 words
The method defined in claim 1 wherein said step of adapting is carried out at regular time intervals.
Claim 5
Dependent Claim
43 words
The method defined in claim 1 wherein said step of adapting includes changing the variable length codeword code corresponding to the values of a group when the statistical frequency of occurrence of the values during a time interval exceeds a given threshold value.
Claim 6
Dependent Claim
18 words
The method defined in claim 4 wherein said step of adapting is carried out at regular time intervals.
Claim 7
Dependent Claim
29 words
The method defined in claim 1 wherein the prescribed variable codeword length code is a standard code which is provided in both the variable codeword length encoder and decoder.
Claim 8
Dependent Claim
33 words
The method defined in claim 1 wherein said step of adapting includes adapting the variable codeword length code based on an absolute probability of appearance of the preceding data in the subsequent data.
Claim 9
Dependent Claim
34 words
The method defined in claim 7 wherein said step of adapting includes adapting the variable codeword length code based exclusively on the absolute probability of appearance of the preceding data in the subsequent data.
Claim 10
Dependent Claim
32 words
The method defined in claim 1 wherein said step of transmitting at least the changes includes transmitting the changes between the defined variable codeword length and the adapted variable codeword length code.
Claim 11
Dependent Claim
26 words
The method defined in claim 1 wherein said step of transmitting at least the changes includes transmitting the changes between two successive adapted variable length codes.
Claim 12
Dependent Claim
16 words
The method defined in claim 1 wherein the variable codeword length code is a Huffman code.
Claim 13
Dependent Claim
17 words
The method defined in claim 1 wherein the data to be transmitted is a digital video signal.
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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) | 1992-06-12 | 1992-12-12 | 1993-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-12 | 1996-12-12 | 1997-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-12 | 2000-12-12 | 2001-06-13 | $7700.00 | Window Closed / Lapsed |