Upper bounds on the free distance for trellis codes combined with CPFSK signals
ELECTRONICS LETTERS, vol.33, no.17, pp.1438-1440, 1997 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 33 Issue: 17
- Publication Date: 1997
- Doi Number: 10.1049/el:19970975
- Journal Name: ELECTRONICS LETTERS
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Page Numbers: pp.1438-1440
- Keywords: trellis codes, communications & signal processing
- Dokuz Eylül University Affiliated: No
Abstract
It is well-known that CPM schemes themselves exhibit attractive spectral efficiencies and that combining them with a rate m/(m + 1) external trellis encoder with 2(m+1)-level modulation results in better power-bandwidth performance. Since the free distance is a good measure of performance, the authors construct upper bounds on the ultimately achievable Free distance for trellis codes of Ungerboeck type combined with constant-envelope CPFSK signals. Some encoders achieving the constructed upper bounds are also presented.