Title :
On good convolutional codes of rate 1/2, 1/3, and 1/4
Author :
Chamber, William G.
Author_Institution :
Dept. of Electron. & Electr. Eng., King´´s Coll. London, UK
Abstract :
Tables are given of convolutional codes of rates 1/2, 1/3, and 1/4 and with generator polynomials of degrees from 6 to 15 (constraint lengths from 7 to 16). This is partly with a view to the use of these codes in direct-sequence spread-spectrum systems, since the asymptotic coding gains of very low-rate convolutional codes are not significantly better than the gains of codes of rate 1/3 and 1/4. Although the free distances of previously published codes are optimal some of the codes given here have fewer adversary paths at the free distance. The improvement in performance is very slight
Keywords :
convolutional codes; asymptotic coding gains; constraint lengths; convolutional codes; direct-sequence spread-spectrum systems; free distances; generator polynomials; rate 1/3; rate 1/4; Additive white noise; Bandwidth; Convolutional codes; Educational institutions; Gain; Gaussian noise; Maintenance; Noise reduction; Spread spectrum communication; Upper bound;
Conference_Titel :
Singapore ICCS/ISITA '92. 'Communications on the Move'
Print_ISBN :
0-7803-0803-4
DOI :
10.1109/ICCS.1992.255163
