Abstract
A multi-class multimedia broadcast/multicast service (MBMS) system includes a transmitter and at least one receiver. The transmitter transmits N primary signals by N primary channels and an auxiliary signal by an auxiliary channel, wherein a resolution of the auxiliary signal is identical to the highest resolution of the N primary signals and the constellation mappings of the auxiliary signal and the primary signal with the highest resolution among said N primary signals on the corresponding modulation constellations are coupled. The receiver couples the primary signal with the corresponding auxiliary/virtual auxiliary signal to obtain a lower-resolution virtual auxiliary signal, which can also be coupled with the primary signal having the same resolution. Therefore, receiving quality of each resolution is improved by combining the primary signal and the corresponding auxiliary/virtual auxiliary signal.