Title :
Double trellis-coded CPM
Author :
Liu, Weiling ; Huber, Johannes
Author_Institution :
Univ. of Fed. Armed Forces Munich, Neubiberg, West Germany
Abstract :
The method of multiple trellis-coded modulation is applied to continuous phase modulation (CPM). Double trellis-coded quaternary CPM schemes using convolutional codes with an effective rate of 2/4 are considered. Tables of optimum codes and minimum Euclidean distances are given for several frequency impulses and ratios of trellis-branches-per-symbol-interval, which have to be processed by a Viterbi-decoder. The results are clearly superior to single trellis-coded schemes with 1/2-rate codes. These improvements are accomplished by a proper selection of double-channel symbols. This method also offers improved receiver implementation properties. For a further reduction of complexity, a modified decision-feedback-sequence estimation is proposed.<>
Keywords :
encoding; phase modulation; CPM; Euclidean distances; Viterbi-decoder; continuous phase modulation; convolutional codes; decision-feedback-sequence estimation; double-channel symbols; multiple trellis-coded modulation; Convolutional codes; Decoding; Feedback; Frequency conversion; Intersymbol interference; Modulation coding; Multidimensional systems; Signal mapping; Signal processing; State estimation;
Conference_Titel :
Communications, 1988. ICC '88. Digital Technology - Spanning the Universe. Conference Record., IEEE International Conference on
Conference_Location :
Philadelphia, PA, USA
DOI :
10.1109/ICC.1988.13834
