Coded continuous phase modulation combined with nonuniform mapping and multi-h scheme

Convolutional coding combined with continuous phase modulation (CPM) has shown the good tradeoff between coding and bandwidth. The authors propose the use of coded CPM with a nonuniform signal constellation and a multihop scheme to achieve further coding gains over the conventional uniform-mapping single-hop coded CPM. The strict bit error probability and the number of merge events are proposed as criteria for evaluating the average performance of the system. With these estimated criteria, the performance of the uniform multihop coded CPM is analyzed. It is found that the nonuniform multihop coded CPM achieves larger Euclidean distance and diminishes the number of merge events up to a certain depth in the state trellis, thereby improving the strict bit error probability