EP0609188A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Erasure decoder and decoding method for use in a concatenated error correcting scheme for data transmission systems
Assignee: The AT&T MVPD Group LLC
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Filing: 1994-01-25
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Granted: —
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Expires: 2014-01-25
Abstract
Abstract A cellular base station receiver uses a digital signal processor to decode receiver code words in an inner Reed-Solomon code loop. A list of code word estimates for the transmitted code word is generated by making different symbol erasure combinations, and a search is made during inner loop processing through all or some of the erasure combinations. An outer cyclic redundancy code loop operates as an error detector for the word estimates. When a code word estimate is found to be error-free, it is accepted for output.
Inventors
- 👤 Andrew J. Macdonald
- 👤 Stanley E. Kay
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 18:16
CPC Classifications
H; H03; H03M; H03M13/00; H03M13/03; H03M13/05; H03M13/13; H03M13/15; H03M13/151; H03M13/154; H03M13/09; H03M13/29; H03M13/2906; H03M13/2909; H03M13/2915; H03M13/2927; H03M13/293; H03M13/37; H03M13/45; H03M13/451; H03M13/453; H03M13/455; H04; H04L; H04L1/00; H04L1/004; H04L1/0045; H04L1/0047; H04L1/005; H04L1/0056; H04L1/0057; H04L1/0064; H04L1/0065; H03M13/1515
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
173 words
A cellular receiver (14A) in a cellular communication system: having means for receiving and demodulating (24) a transmitted signal representing a code word containing a message encoded in an outer code loop (31) with an error detecting code and encoded in an inner code loop (33) with an error correcting code and further having means for decoding (36) the demodulated signal, the cellular receiver characterized by: means for generating a list (38) of estimates of the code word from the demodulated signal; means for operating an error correcting decoder (37) with the error correcting code to decode estimates of the code word; means for operating an error detector decoder (39) with the error detecting code to process decoded code word estimates and determine whether an error exists in each decoded code word estimate that is processed; means for generating (40) as an output signal any decoded code word estimate detected to be error-free; and means for generating (42) a code word error if no decoded code word estimate is detected to be error-free.
Claim 2
Dependent Claim
27 words
A cellular base station having the cellular receiver of claim 1 and further characterized by: means for coupling receiver output signals to a public telephone system (18).
Claim 3
Dependent Claim
25 words
The cellular receiver of claim 1 wherein the error correcting code is the Reed-Solomon code and the error detecting code is a cyclic redundancy code.
Claim 4
Dependent Claim
88 words
The cellular receiver of claim 3 wherein each code word has a predetermined number p of symbols and a predetermined number n of symbol positions are selected for erasure, and further characterized by the list of code word estimates being formed from all possible symbol erasure combinations, and the code word estimates being processed by the error detecting means in a predetermined order until an error-free code word estimate is found or until all code word estimates have been processed and no error-free code word estimate is found.
Claim 5
Dependent Claim
123 words
The cellular receiver of claim 3 wherein each code word has a predetermined number p of symbols and a predetermined number n of symbol positions are selected for erasure and further characterized by: means being provided for determining (41, 43, 45) the reliability of each code word symbol and for selecting those symbols for erasure that have a reliability below a predetermined level; the list of code word estimates being formed from all possible erasure combinations of the selected less reliable symbols; and the code word estimates being processed by the error detecting means in a predetermined order until an error-free code word estimate is found or until all code word estimates have been processed and no error-free code word estimate is found.
Claim 6
Dependent Claim
30 words
The cellular receiver of claim 5 wherein the predetermined order for processing the code word estimates is in reliability order from the least reliable estimate to the most reliable estimate.
Claim 7
Dependent Claim
47 words
The cellular receiver of claim 5 wherein the reliability determining means is further characterized by: means for generating (45) hard bit values from soft bit values (43) derived from the transmitted signal; and means for generating (41) symbol reliability values from the soft and hard bit values.
Claim 8
Dependent Claim
28 words
The cellular receiver of claim 1 further characterized by: means (41) for processing digital signals, the digital signal processing means including the operating means and the generating means.
Claim 9
Dependent Claim
32 words
The cellular receiver of claim 7 further characterized by: means (41) for processing digital signals, the digital signal processing means including the operating means, the generating means and the reliability determining means.
Claim 10
Independent Claim
176 words
A method for operating a cellular receiver in a cellular communication system: having means for receiving and demodulating (24) a transmitted signal representing a code word containing a message encoded in an outer code loop (31) with an error detecting code and encoded in an inner code loop (33) with an error correcting code and further having means for decoding (36) the demodulated signal, the cellular receiver characterized by: means for generating a list (38) of estimates of the code word from the demodulated signal; means for operating an error correcting decoder (37) with the error correcting code to decode estimates of the code word; means for operating an error detector decoder (39) with the error detecting code to process decoded code word estimates and determine whether an error exists in each decoded code word estimate that is processed; means for generating (40) as an output signal any decoded code word estimate detected to be error-free; and means for generating (42) a code word error if no decoded code word estimate is detected to be error-free.
References Cited (Backward Citations)
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