US5524025A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coding for digital transmission
Assignee: AT&T Inc
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Filing: 1992-11-16
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Granted: 1996-06-04
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Expires: 2012-11-16
Abstract
Abstract Digital signals, such as digitized television signals, are subjected to a source coding step followed by a channel mapping step. The source coding step causes the television signal to be represented by two or more data streams while, in the channel mapping step, the mapping is such that the data elements of the various data streams have differing probabilities of being erroneously detected at the receiver. In preferred embodiments, a first one of the aforementioned data streams carries components of the overall television signal which are regarded as the most important-for example the audio, the framing information, and the vital portions of the video information, such as motion compensation information-and that data stream is mapped such that its data elements have the lowest probability of error. A second one of the data streams carries components of the overall television signal which are regarded as less important than those of the first data stream and that data stream is mapped such that its data elements have a probability of error that is not as low as those of the first data stream. In general, it is possible to represent the overall television signal with any number of data streams, each carrying components of varying importance and each having a respective probability of error. This approach allows a graceful degradation in reception quality at, for example, the television set location because as the bit error rate at the receiver begins to increase with increasing distance from the broadcast transmitter, the bits that represent proportionately less of the video information will be the first to be affected.
Inventors
- 👤 Victor B. Lawrence
- 👤 Arun N. Netravali
- 👤 Jean-Jacques Werner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:59
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/32; H04L27/34; H04L27/3405; H04L27/3416; H04L27/3427; H04N; H04N7/00; H04N7/12; H04L27/3488; H04N21/00; H04N21/40; H04N21/41; H04N21/426; H04N7/08
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
88 words
A method for communicating television information, comprising the steps of: generating a digital signal representing non-time domain information in a television signal, the digital signal being comprised of at least first and second streams of data elements, channel mapping the digital signal, and transmitting the mapped signal over a communication channel, the mapping step being such that the probability of channel-induced bit error for the data elements of the first stream is less than the probability of channel-induced bit error for the data elements of the second stream.
Claim 2
Independent Claim
88 words
A method for communicating television information, comprising the steps of: generating a digital signal representing non-time domain information in a television signal, the digital signal being comprised of at least first and second streams of data elements, channel mapping the digital signal, and transmitting the mapped signal over a communication channel, the mapping step being such that the probability of channel-induced bit error for the data elements of the first stream is less than the probability of channel-induced bit error for the data elements of the second stream.
Claim 3
Dependent Claim
12 words
The invention of claim 1 wherein said information is television signal information.
Claim 4
Dependent Claim
18 words
The invention of claim 1 wherein said mapping step includes the step of trellis coding the digital signal.
Claim 5
Dependent Claim
26 words
The invention of claim 1 wherein said generating step includes the steps of receiving the information, and source coding the information using a predetermined source code.
Claim 6
Dependent Claim
19 words
The method of claim 1, in which the non-time domain information comprises transform coefficients produced from the television signal.
Claim 7
Dependent Claim
15 words
The method of claim 5, in which the transform coefficients are discrete cosine transform coefficients.
Claim 8
Dependent Claim
61 words
The method of claim 5, in which the first and second data streams each comprise one or more quantized transform coefficients, the transform coefficients in the first data stream being quantized at a first level and the transform coefficients in the second data stream being quantized at the second level, the first quantization level being finer than the second quantization level.
Claim 9
Dependent Claim
44 words
The method of claim 1, in which the first and the second data streams each comprise one or more transform coefficients, the transform coefficients in the first data stream representing a greater amount of energy than the transform coefficients in the second data stream.
Claim 10
Dependent Claim
43 words
The method of claim 1, in which the first and second data streams each comprise one or more transform coefficients, the transform coefficients in the first data stream each having a greater perceptual importance than the transform coefficients in the second data stream.
Claim 11
Dependent Claim
30 words
The method of claim 9, in which the coefficients in the first data stream represent low frequency information and the coefficients in the second data stream represent high frequency information.
Claim 12
Dependent Claim
28 words
The method of claim 9, in which the coefficients in the first data stream represent edge information and the coefficients in the second data stream represent non-edge information.
Claim 13
Dependent Claim
29 words
The method of claim 1, in which the generating step comprises the steps of: generating a motion compensated prediction error signal; and generating transform coefficients from the error signal.
Claim 14
Dependent Claim
89 words
Apparatus for communicating television information, comprising: means for generating a digital signal representing non-time domain information in a television signal, the digital signal being comprised of at least first and second streams of data elements, means for mapping the digital signal, and means for transmitting the mapped signal over a communication channel, the mapping means being such that the probability of channel-induced bit error for the data elements of the first stream is less than the probability of channel-induced bit error for the data elements of the second stream.
Claim 15
Dependent Claim
89 words
Apparatus for communicating television information, comprising: means for generating a digital signal representing non-time domain information in a television signal, the digital signal being comprised of at least first and second streams of data elements, means for mapping the digital signal, and means for transmitting the mapped signal over a communication channel, the mapping means being such that the probability of channel-induced bit error for the data elements of the first stream is less than the probability of channel-induced bit error for the data elements of the second stream.
Claim 16
Dependent Claim
29 words
The invention of claim 13 wherein said digital signal generating means includes means for receiving the information, and means for source coding the information using a predetermined source code.
Claim 17
Dependent Claim
149 words
An arrangement for use in a television receiver which receives intelligence communicated to said receiver by a television transmitter, said transmitter including apparatus for a) generating a digital signal representing non-time domain information derived from a television signal, the digital signal being comprised of at least first and second streams of data elements; b) channel mapping the digital signal using a predetermined signal constellation; and c) transmitting the mapped signal over a communication channel to the receiver, said mapping being such that the probability of channel-induced bit error for the data elements of the first stream is less than the probability of channel-induced bit error for the data elements of the second stream, said arrangement comprising: means for receiving the transmitted signal, and means for storing information relating to said signal constellation and for recovering said non-time domain information from the received signal in response to said stored information.
Claim 18
Dependent Claim
149 words
An arrangement for use in a television receiver which receives intelligence communicated to said receiver by a television transmitter, said transmitter including apparatus for a) generating a digital signal representing non-time domain information derived from a television signal, the digital signal being comprised of at least first and second streams of data elements; b) channel mapping the digital signal using a predetermined signal constellation; and c) transmitting the mapped signal over a communication channel to the receiver, said mapping being such that the probability of channel-induced bit error for the data elements of the first stream is less than the probability of channel-induced bit error for the data elements of the second stream, said arrangement comprising: means for receiving the transmitted signal, and means for storing information relating to said signal constellation and for recovering said non-time domain information from the received signal in response to said stored information.
Claim 19
Dependent Claim
15 words
The invention of claim 15 wherein said television signal is a high definition television signal.
Claim 20
Dependent Claim
24 words
The invention of claim 15 wherein said mapping includes trellis coding of the digital signal and wherein said recovering means includes a maximum-likelihood decoder.
Claim 21
Dependent Claim
46 words
The invention of claim 15 wherein said mapping includes the selecting of a sequence of signal points from a predefined constellation of signal points to represent the data elements and wherein said stored information is indicative of the positions of the signal points of said constellation.
Claim 22
Dependent Claim
14 words
The invention of claim 18 wherein said constellation is an N-dimensional constellation, where N≧2.
Claim 23
Independent Claim
94 words
A method for communicating television information, comprising the steps of: generating a digital signal representing at least a portion of said information in other than the time domain, the digital signal being comprised of at least first and second streams of data elements, channel mapping the digital signal, and transmitting the mapped signal over a communication channel, the mapping step being such that the probability of channel-induced bit error for the data elements of the first stream is less than the probability of channel-induced bit error for the data elements of the second stream.
Claim 24
Independent Claim
94 words
A method for communicating television information, comprising the steps of: generating a digital signal representing at least a portion of said information in other than the time domain, the digital signal being comprised of at least first and second streams of data elements, channel mapping the digital signal, and transmitting the mapped signal over a communication channel, the mapping step being such that the probability of channel-induced bit error for the data elements of the first stream is less than the probability of channel-induced bit error for the data elements of the second stream.
Claim 25
Dependent Claim
14 words
The method of claim 20, in which the first data stream comprises framing information.
Claim 26
Dependent Claim
14 words
The method of claim 20, in which the first data stream comprises audio information.
Claim 27
Independent Claim
88 words
A method for communicating television information, comprising the steps of: generating a digital signal representing transform coefficients derived from a television signal, the digital signal being comprised of at least first and second streams of data elements, channel mapping the digital signal, and transmitting the mapped signal over a communication channel, the mapping step being such that the probability of channel-induced bit error for the data elements of the first stream is less than the probability of channel-induced bit error for the data elements of the second stream.
Claim 28
Independent Claim
88 words
A method for communicating television information, comprising the steps of: generating a digital signal representing transform coefficients derived from a television signal, the digital signal being comprised of at least first and second streams of data elements, channel mapping the digital signal, and transmitting the mapped signal over a communication channel, the mapping step being such that the probability of channel-induced bit error for the data elements of the first stream is less than the probability of channel-induced bit error for the data elements of the second stream.
Claim 29
Independent Claim
80 words
A method for communicating television information, comprising the steps of: generating a digital signal representing a discrete transform of a television signal, the digital signal comprising a first data element and a second data element; channel mapping the digital signal; and transmitting the mapped signal over a communications channel, the mapping step being such that the probability of channel induced error for the first data element is less than the probability of channel induced error for the second data element.
Claim 30
Independent Claim
80 words
A method for communicating television information, comprising the steps of: generating a digital signal representing a discrete transform of a television signal, the digital signal comprising a first data element and a second data element; channel mapping the digital signal; and transmitting the mapped signal over a communications channel, the mapping step being such that the probability of channel induced error for the first data element is less than the probability of channel induced error for the second data element.
Claim 31
Dependent Claim
17 words
The method of claim 24, in which the discrete transform comprises coefficients derived from a television signal.
Claim 32
Dependent Claim
14 words
The method of claim 25, in which the coefficients are discrete cosine transform coefficients.
Claim 33
Dependent Claim
59 words
The method of claim 24, in which the first data element represents a first amount of energy in the television signal and the second data element represents a second amount of energy in the television signal, in which the first data element represents a greater amount of energy than the amount of energy represented by the second data element.
Claim 34
Dependent Claim
68 words
The method of claim 24, in which the first data element represents a characteristic of the television signal having a first perceptual importance and the second data element represents a characteristic of the television signal having a second perceptual importance, in which the characteristic represented by the first data element has a perceptual importance greater than the perceptual importance of the characteristic represented by the second data element.
Claim 35
Dependent Claim
24 words
The method of claim 24, in which the first data element represents low frequency information and the second data element represents high frequency information.
Claim 36
Dependent Claim
22 words
The method of claim 24, in which the first data element represents edge information and the second data element represents non-edge information.
Claim 37
Dependent Claim
29 words
The method of claim 24, in which the generating step comprises the steps of: generating a motion compensated prediction error signal; and generating transform coefficients from the error signal.
Claim 38
Dependent Claim
53 words
The method of claim 24, in which the first and second data elements comprise respective first and second quantized transform coefficients, the first transform coefficient being quantized at a first level and the second transform coefficient being quantized at a second level, the first quantization level being finer than the second quantization level.
Claim 39
Dependent Claim
14 words
The method of claim 24, in which the first data element represents framing information.
Claim 40
Dependent Claim
14 words
The method of claim 24, in which the first data element represents audio information.
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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) | 1999-06-04 | 1999-12-04 | 2000-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-06-04 | 2003-12-04 | 2004-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-06-04 | 2007-12-04 | 2008-06-04 | $7700.00 | Window Closed / Lapsed |