Patent ID: 7917830
Filing Date: 2011-03-29
Classification: H03M

Abstract:
1. A turbo decoder for receiving a systematic code, a first parity code, and a second parity code through a communication link and performing several iteration to do decoding, the turbo decoder comprising: a first interleaver for receiving the systematic code and processing the systematic code into an interleaved systematic code; a first component decoder and a second component decoder for respectively getting first extrinsic information according to the systematic code, the first parity code and a first a-priori information and getting second extrinsic information according to the interleaved systematic code, the second parity code and a second a-priori information; a second interleaver for processing the first extrinsic information into the second a-priori information; a de-interleaver for processing the second extrinsic information into the first a-priori information, wherein the formats of the first extrinsic information and the second extrinsic information are respectively the same as formats of the first a-priori information and the second a-priori information; and a stop judging circuit, which comprises: a signal selector for responding with a first level of a select signal to select the first extrinsic information and the first a-priori information as a first output data and a second output data for output, and responding with a second level of the select signal to select the second extrinsic information and the second a-priori information as the first output data and the second output data for output; a difference detector for detecting a difference between the first output data and the second output data to get difference data; and a comparator for judging whether the difference data is smaller than a threshold value, and outputting a stopping signal to stop the iteration of the turbo decoder when the difference data is smaller than the threshold value; wherein the first component decoder and the second component decoder further respectively receive the first and the second a-priori information and adjust the new first extrinsic information and the new second extrinsic information to perform the iteration according to the first and the second a-priori information.