Title :
A note on type II convolutional codes
Author :
Johannesson, Rolf ; Ståhl, Per ; Wittenmark, Emma
Author_Institution :
Dept. of Inf. Theory, Lund Univ., Sweden
fDate :
7/1/2000 12:00:00 AM
Abstract :
The result of a search for the world´s second type II (doubly-even and self-dual) convolutional code is reported. A rate R=4/8, 16-state, time-invariant, convolutional code with free distance dfree=8 was found to be type II. The initial part of its weight spectrum is better than that of the Golay convolutional code (GCC). Generator matrices and path weight enumerators for some other type II convolutional codes are given. By the “wrap-around” technique tail-biting versions of (32, 18, 8) Type II block codes are constructed
Keywords :
binary codes; block codes; convolutional codes; dual codes; matrix algebra; Golay convolutional code; binary codes; doubly-even convolutional code; free distance; generator matrices; path weight enumerators; self-dual convolutional code; tail-biting type II block codes; time-invariant convolutional code; type II convolutional codes; wrap-around technique; Block codes; Convolutional codes; Councils; Delay; Information technology; Information theory; Mobile communication;
Journal_Title :
Information Theory, IEEE Transactions on
