| 摘要 |
In a modulation system for sending digital symbols over a band-limited channel in accordance with a sequence of multi-dimensional points each composed of a plurality of two-dimensional modulation signal points, and each selected from an available alphabet of the multi-dimensional points by an encoder on the basis of a group of the digital symbols, the improvement which includes circuitry for accumulating the symbols of each group, and circuitry for thereafter selecting the multi-dimensional point for the group, and in which the available alphabet includes a plurality of subsets of the multi-dimensional points, and the subset from which the multi-dimensional point is selected for each group depends on the subset from which the multi-dimensional point is selected for another one of the groups.
|
