Upper bounds on the free distance for a class of convolutional coded CPFSK signals


Ertas T.

IEEE COMMUNICATIONS LETTERS, vol.5, no.12, pp.483-485, 2001 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 5 Issue: 12
  • Publication Date: 2001
  • Doi Number: 10.1109/4234.974493
  • Title of Journal : IEEE COMMUNICATIONS LETTERS
  • Page Numbers: pp.483-485

Abstract

In this letter, we construct new encoder-independent upper bounds on the free distance for the rate (n-1)/n convolutional encoders that are formed by using rate 1/2 encoders and combined with 2(n)-level constant-envelope full-response CPFSK signals of single-h, by generalizing the bounding technique employed for the existing bounds. The new bounds coincide with the existing bounds for hless than or equal to0.25, but are generally better for h>0.25. We also present actual encoder combinations achieving the constructed new bounds with short constraint lengths.