Multiresolution broadcast transmitter and method using Gaussian trellis shaping to reduce average signal power and corresponding multi-stage decoder

摘要

A transmitter, a broadcast signal, a multi-stage decoder and a method for generating said broadcast signal are described, whereby a multiresolution hierarchical modulation scheme with unequal error protection is used. Within each quality level (qi) of the hierarchical modulation scheme, the signal probability distribution is shaped individually using trellis shaping (22). Unequally distributed probabilities are assigned to the hyper constellation points u1,k within a quality level i, and thus the average transmit power is reduced. Preferably, as a probability distribution, a discrete Gaussian distribution is used.