Further results on binary convolutional codes with an optimum distance profile (Corresp.)

Author

Johannesson, Rolf ; Paaske, Erik

Volume

24

Issue

2

fYear

1978

fDate

3/1/1978 12:00:00 AM

Firstpage

264

Lastpage

268

Abstract

Fixed binary convolutional codes are considered which are simultaneously optimal or near-optimal according to three criteria: namely, distance profile $d$ , free distance $d_{ \\infty }$ , and minimum number of weight $d_{\\infty }$ paths. It is shown how the optimum distance profile criterion can be used to limit the search for codes with a large value of $d_{\\infty }$ . We present extensive lists of such robustly optimal codes containing rate $R = l/2$ nonsystematic codes, several with $d_{\\infty }$ superior to that of any previously known code of the same rate and memory; rate $R = 2/3$ systematic codes; and rate $R = 2/3$ nonsystematic codes. As a counterpart to quick-look-in (QLI) codes which are not "transparent," we introduce rate $R = 1/2$ easy-look-in-transparent (ELIT) codes with a feedforward inverse $(1 + D,D)$ . In general, ELIT codes have $d_{\\infty }$ superior to that of QLI codes.

Keywords

Convolutional codes; Convolutional codes; Decoding; Error correction codes; Error probability; Hamming weight; Polynomials; Robustness; Viterbi algorithm;

fLanguage

English

Journal_Title

Information Theory, IEEE Transactions on

Publisher

ieee

ISSN

0018-9448

Type

jour

DOI

10.1109/TIT.1978.1055850

Filename

1055850