DocumentCode :
16341
Title :
Gallager B LDPC Decoder with Transient and Permanent Errors
Author :
Chu-Hsiang Huang ; Yao Li ; Dolecek, Lara
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of California-Los Angeles (UCLA), Los Angeles, CA, USA
Volume :
62
Issue :
1
fYear :
2014
fDate :
Jan-14
Firstpage :
15
Lastpage :
28
Abstract :
This paper studies the performance of a noisy Gallager B decoder for regular LDPC codes. We assume that the noisy decoder is subject to both transient processor errors and permanent memory errors. We permit different error rates at different functional components. In addition, for the sake of generality, we allow asymmetry in the permanent error rates of component outputs, and thus we model error propagation in the decoder via a suitable asymmetric channel. We then develop a density evolution-type analysis on this asymmetric channel. The recursive expression for the bit error probability is derived as a function of the code parameters (node degrees), codeword weight, transmission error rate, and the error rates of the permanent and the transient errors. Based on this analysis, we then derive the residual error of the Gallager B decoder for the regime where the transmission error rate and the processing error rates are small. In this regime, we further observe that the residual error rate can be well approximated by a suitable combination of the transient error rate and the permanent error rate at variable nodes, provided that the check node degree is large enough. Based on this insight, we then propose and analyze a scheme for detecting permanent errors and correcting detected residual errors. The scheme exploits the parity check equations of the code and reuses the existing hardware to locate permanent errors in memory blocks. Performance analysis and simulation results show that, with high probability, the detection scheme discovers correct locations of permanent memory errors, while, with low probability, it mislabels the functional memory as being defective. The proposed error detection-and-correction scheme can be implemented in-circuit and is useful in combating failures arising from aging.
Keywords :
parity check codes; probability; bit error probability; code parameters; density evolution-type analysis; error detection-and-correction scheme; error propagation; noisy Gallager B LDPC decoder; parity check equations; permanent error rates; permanent memory errors; regular LDPC codes; transient processor errors; Decoding; Error analysis; Hardware; Mathematical model; Noise measurement; Parity check codes; Transient analysis; Gallager B decoder; faulty gates; permanent errors; processing noise;
fLanguage :
English
Journal_Title :
Communications, IEEE Transactions on
Publisher :
ieee
ISSN :
0090-6778
Type :
jour
DOI :
10.1109/TCOMM.2013.111913.130178
Filename :
6679370
Link To Document :
بازگشت