  Broadcasting systems have to deal with channel variability in order to offer
the best rate to the users. Hierarchical modulation is a practical solution to
provide different rates to the receivers in function of the channel quality.
Unfortunately, the performance evaluation of such modulations requires time
consuming simulations. We propose in this paper a novel approach based on the
channel capacity to avoid these simulations. The method allows to study the
performance of hierarchical and also classical modulations combined with error
correcting codes. We will also compare hierarchical modulation with time
sharing strategy in terms of achievable rates and indisponibility. Our work
will be applied to the DVB-SH and DVB-S2 standards, which both consider
hierarchical modulation as an optional feature.
