Convolutional codes over GF(4) for 4-ary distance-invariant CPFSK signalling
Nodar Ugrelidze, Sergo Shavgulidze, I.G. Asanidze · Electronics Letters · 1993
Combinations of new convolutional codes over GF(4) and 4-ary distance-invariant CPFSK modulation are considered. The best codes that ensure maximum free Euclidean distance in signal space are given in a Table. The convolutional codes are termed, ‘concordant’ because their trellis diagram topologically coincides with the joint signal-code trellis diagram.