摘要 |
Source symbols are encoded for use in a higher level modulator by partitioning the source symbols into a number of classes. This principle is applied in a number of alternative transmitter and receiver embodiments. In one embodiment, a corresponding encoder is provided for each of the classes, and for each class, each of the source symbols is supplied to the corresponding encoder. For each encoder, coded symbols are supplied at an encoder output and the coded symbols are partitioned into a number of levels associated with the corresponding class, wherein at least one of the classes has at least two levels assigned to it. The partitioned coded symbols are then supplied to a mapper that generates amplitude coefficient signals. Corresponding receivers perform inverse operations to those performed by the transmitters.
|