EP0531046A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Multi-subcarrier modulation for HDTV transmission
Assignee: AT&T Inc
•
Filing: 1992-08-27
•
Granted: —
•
Expires: 2012-08-27
Abstract
Abstract A high definition television (HDTV) signal is transmitted by a multi-subcarrier transmitter (100) in which each subcarrier (f1,f2...f12) is used to carry a different class of HDTV information. <IMAGE>
Inventors
- 👤 Lee-Fang Wei
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 10:47
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/12; H04N21/00; H04N21/20; H04N21/23; H04N21/238; H04N21/2383; H04L; H04L27/00; H04L27/26; H04L27/2601; H04L27/2602; H04L27/2604; H04N21/40; H04N21/43; H04N21/438; H04N21/4382; H04N7/015; H04N7/08; H04N7/0806
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
112 words
A method for processing an information signal comprising the steps of separaring the information signal into a plurality of classes of information such that at least one of the plurality of classes of information is more important for reception of the information signal than the other ones of the plurality of classes of information, encoding the plurality of classes of information to provide a plurality of encoded symbols such that the more important information has more error protection than the remaining ones of the plurality of classes of information, and modulating the plurality of encoded symbols into a plurality of subchannels within a frequency band, each subchannel occupying a different frequency spectrum.
Claim 2
Dependent Claim
15 words
The method of claim 1 wherein the frequency band is assigned to a different signal.
Claim 3
Dependent Claim
27 words
The method of claim 2 wherein the modulating step places the more important information into a subchannel that does not contain a carrier of the different signal.
Claim 4
Dependent Claim
52 words
The method of claim 1 wherein the encoding step includes the steps of channel encoding each one of the plurality of classes of information to provide a plurality of encoded outputs, and mapping each one of the plurality of encoded outputs to a signal constellation to provide the plurality of encoded symbols.
Claim 5
Dependent Claim
34 words
The method of claim 4 wherein the channel encoding step for the more important information is different from the channel encoding step of at least one other of the plurality of classes of information.
Claim 6
Dependent Claim
18 words
The method of claim 5 wherein the channel encoding step operates in accordance with an error correcting code.
Claim 7
Dependent Claim
16 words
The method of claim 5 wherein the channel encoding step operates in accordance with coded modulation.
Claim 8
Dependent Claim
21 words
The method of claim 5 wherein the channel encoding step operates in accordance with coded modulation and an error correcting code.
Claim 9
Dependent Claim
41 words
The method of claim 4 wherein the mapping step for the more important information uses a signal point constellation that is different from at least one other of the signal point constellations used for the other plurality of classes of information.
Claim 10
Dependent Claim
35 words
The method of claim 1 wherein the encoding step uses a symbol rate for the more important class of information that is different from the symbol rate of a least one other class of information.
Claim 11
Dependent Claim
140 words
Apparatus for processing an information signal comprising means for separating the information signal into a plurality of classes of information such that at least one of the plurality of classes of information is more important than the other ones of the plurality of classes of information for reception of the information signal, means for providing unequal levels of error protection to the plurality of classes of information to provide a plurality of encoded symbols for each one of the plurality of classes of information such that the more important information has more error protection than the remaining ones of the plurality of classes of information, and means for modulating the plurality of encoded symbols for each one of the plurality of classes of information to a plurality of subchannels within a frequency band, each subchannel occupying a different frequency spectrum.
Claim 12
Dependent Claim
15 words
The apparatus of claim 11 wherein the frequency band is assigned to a different signal.
Claim 13
Dependent Claim
28 words
The apparatus of claim 12 wherein the means for modulating places the more important information into a subchannel that does not contain a carrier of the different signal.
Claim 14
Dependent Claim
58 words
The apparatus of claim 11 wherein the means for providing unequal error protection further comprises channel encoding means for each one of the plurality of classes of information to provide a plurality of encoded outputs, and means for mapping each one of the plurality of encoded outputs to a signal constellation to provide the plurality of encoded symbols.
Claim 15
Dependent Claim
34 words
The apparatus of claim 14 wherein the channel encoding means for the more important information is different from the channel encoding means of at least one other of the plurality of classes of information.
Claim 16
Dependent Claim
41 words
The apparatus of claim 14 wherein the means for mapping the more important information uses a signal point constellation that is different from at least one other of the signal point constellations used for the other plurality of classes of information.
Claim 17
Dependent Claim
39 words
The apparatus of claim 11 wherein the means for providing unequal error protection uses a symbol rate for the more important class of information that is different from the symbol rate of at least one other class of information.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.