Error detection/correction and fault detection/recovery – Pulse or data error handling – Digital data error correction
Patent
1997-08-27
2000-07-04
De Cady, Albert
Error detection/correction and fault detection/recovery
Pulse or data error handling
Digital data error correction
714779, H03M 1300
Patent
active
060853492
ABSTRACT:
The method for selecting CRC polynomials (or CRC generators) for linear coded systems. In the exemplary embodiment, a communication system utilizes a concatenated code comprising a CRC code and a convolutional code. The CRC generators are selected based on the distance spectrums which have been computed for all possible CRC generators of a given length L. The distance spectrum comprises a listing of the number of paths (or code words) at various weights (or Hamming distance). These paths represent error information sequences I(x) which have diverged from an all-zero transmitted sequence (or the zero state) and have merged back into the zero state. The paths are checked by the CRC generators. If the CRC check passes, indicating that the error information sequence is undetected by the CRC check, the weight of this path is calculated and the distance spectrum for this CRC generator is updated. Otherwise, if the CRC does not check, the path is ignored. The CRC generator with the maximum minimum distance d.sub.min is selected.
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Cady Albert De
Chase Shelly A
Macek Kyong H.
Miller Russell B.
Qualcomm Incorporated
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