| 摘要 |
System and Device for, and Method of, Communicating According to a Trellis Code of Baseband Signals Chosen from a Fixed Set of Baseband Signal Points. Signal points are chosen from a fixed set of signal points, such as exists in the baseband signal points found in PSTN companding algorithms. These signal points are assingned to subsets and transmitted according to a predefined transmitter state sequence, representable as a trellis diagram. The subsets may overlap by sharing signal points. The sharing of signal points improves the transmission performance of the arrangement in comparison to conventional disjoint sets. The signal points are selected and associated with subsets, such that the signal points transmittable from a given transmitter states maintain a minimum distance of d, even though the full combination of signal points of all subsets need not satisfy a minimum distance of d/2. From time-to-time, disjoint subsets may be used to preclude decoding problems resulting from the quasi catastrophic aspects of the resulting code.
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