Apparatus and method for error correction in a CDMA mobile communication system
AssigneeSamsung Electronics Co., Ltd.
InventorsNam-Yul Yu, Min-Goo Kim
Life of this patent
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Abstract
An FEC apparatus and method is provided that uses turbo codes. An input frame is iteratively decoded until an iterative decoding stop command is received under a predetermined control, and the absolute reliability of each symbol in the frame is output. The minimum of the absolute reliabilities is detected as a measurement, and a threshold is detected using the a-priori information and extrinsic information of the each symbol. The measurement is compared with the threshold, and the iterative decoding stop command is output according to the comparison result.
Claims6
A forward error correction apparatus using turbo codes, comprising:
- a decoder for iteratively decoding an input frame on a symbol basis until an iterative decoding stop command is received under a predetermined control, and outputting an absolute reliability of symbols in the frame and a-prior information and extrinsic information for the symbols;
- a measurement detector for detecting a minimum of the absolute reliabilities as a measurement;
- a threshold detector for detecting a threshold comprising a number of different signs of a-priori information and extrinsic information for the symbols wherein the threshold detector comprises an OR gate for performing logical OR-operation on the signs of the a-priori information with the signs of the extrinsic information, a counter for receiving a signal from the OR gate and counting a number of the different signs between the a-priori information and the extrinsic information and a multiplier for multiplying the counted number of different signs from the counter by a compensation value according to quantization of the symbols input to the decoder;
- a comparator for comparing the measurement with the threshold;
- and
- a controller for receiving a comparison result from the comparator and outputting the iterative decoding stop command according to the comparison result.
A forward error correction method using turbo codes, comprising:
- iteratively decoding an input frame on a symbol basis until an iterative decoding stop command is received under a predetermined control, and outputting the absolute reliability of symbols in the frame and a-priori information and extrinsic information for the symbols;
- detecting a minimum of the absolute reliabilities as a measurement;
- detecting a threshold comprising a number of different signs of a-priori information and extrinsic information for the symbols wherein the step of detecting a threshold comprises performing a logical OR-operation on the signs of the a-priori information with the signs of the extrinsic information, counting the number of the different signs between the a-priori information and the extrinsic information using an OR-operated value and multiplying the counted number of different signs by a compensation value according to quantization of the symbol input to the decoder;
- comparing the measurement with the threshold;
- and
- outputting the iterative decoding stop command according to the comparison result.
Dependencies are inferred from the claim text.