DocumentCode :
3501587
Title :
Nonuniform codes for correcting asymmetric errors
Author :
Zhou, Hongchao ; Jiang, Anxiao ; Bruck, Jehoshua
Author_Institution :
Electr. Eng. Dept., California Inst. of Technol., Pasadena, CA, USA
fYear :
2011
fDate :
July 31 2011-Aug. 5 2011
Firstpage :
1046
Lastpage :
1050
Abstract :
Codes that correct asymmetric errors have important applications in storage systems, including optical disks and Read Only Memories. The construction of asymmetric error correcting codes is a topic that was studied extensively, however, the existing approach for code construction assumes that every codeword could sustain t asymmetric errors. Our main observation is that in contrast to symmetric errors, where the error probability of a codeword is context independent (since the error probability for 1s and 0s is identical), asymmetric errors are context dependent. For example, the all-1 codeword has a higher error probability than the all-0 codeword (since the only errors are 1 → 0). We call the existing codes uniform codes while we focus on the notion of nonuniform codes, namely, codes whose codewords can tolerate different numbers of asymmetric errors depending on their Hamming weights. The goal of nonuniform codes is to guarantee the reliability of every codeword, which is important in data storage to retrieve whatever one wrote in. We prove an almost explicit upper bound on the size of nonuniform asymmetric error correcting codes and present two general constructions. We also study the rate of nonuniform codes compared to uniform codes and show that there is a potential performance gain.
Keywords :
error correction codes; error statistics; optical disc storage; read-only storage; telecommunication network reliability; Hamming weights; asymmetric error correcting codes; code construction; codeword; data storage; error probability; general constructions; nonuniform codes; optical disks; read only memories; symmetric errors; Decoding; Error correction codes; Hamming weight; Linear code; Upper bound; Zirconium;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Information Theory Proceedings (ISIT), 2011 IEEE International Symposium on
Conference_Location :
St. Petersburg
ISSN :
2157-8095
Print_ISBN :
978-1-4577-0596-0
Electronic_ISBN :
2157-8095
Type :
conf
DOI :
10.1109/ISIT.2011.6033689
Filename :
6033689
Link To Document :
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