DocumentCode
1261235
Title
An ENDEC for high rate quadbit mod 2 codes
Author
Livingston, J.N. ; Bliss, William G.
Author_Institution
Cirrus Logic, Broomsfield, CO, USA
Volume
35
Issue
5
fYear
1999
fDate
9/1/1999 12:00:00 AM
Firstpage
2298
Lastpage
2300
Abstract
Quadbit Module 2 (QM2) constraint codes are similar to Tribit Module 2 codes, and have a Shannon capacity of 0.9613. QM2 codes disallow all pentabits and longer in NRZI space, and allow quadbits to occur only on even time indices. This constraint removes a class of error events, and improves performance. In order to achieve rates close to capacity, larger block sizes must be used. This paper describes a method for encoding high rate QM2 codes. The method uses sets of subsequences to form the large block size codewords, and is memory efficient, requiring less than 256 bytes for a rate 15/16 code
Keywords
computational complexity; error correction codes; magnetic recording; sequential codes; ENDEC; Quadbit Module 2 constraint codes; Shannon capacity; Tribit Module 2 codes; block sizes; codewords; encoding; error events; even time indices; high rate QM2 codes; magnetic recording; performance; rate 15/16 code; subsequences; Block codes; Logic; Table lookup;
fLanguage
English
Journal_Title
Magnetics, IEEE Transactions on
Publisher
ieee
ISSN
0018-9464
Type
jour
DOI
10.1109/20.800805
Filename
800805
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