CONSTELLATION RATIO FOR A HIERARCHICAL MODULATION SIGNAL

摘要

A method of obtaining N values of a constellation ratio α for use when transmitting a hierarchical modulation (HM) signal comprises obtaining a model of the variation in a minimum signal-to-noise ratio (SNR) required to provide a predetermined performance measure at a receiver, as a function of α, selecting N target SNR values, and obtaining each of the N values of α, based on the model, by obtaining the value of α corresponding to each of the target SNR values. The performance measure can be a parameter relating to received signal quality, for example the bit error rate, packet error rate, or block error rate. Apparatus for transmitting an HM signal can select one of the N values obtained using the method, and transmit the HM signal based on the selected value of the constellation ratio. Apparatus for receiving an HM signal can receive information for identifying one of the N values obtained using the method, and decode the received HM signal based on the identified value of the constellation ratio.