@ARTICLE {2257,
author={N.S. Souto and Cercas, F. Cercas and J. C. Silva},
doi={10.1109/TCOMM.2007.906367},
journal={IEEE Transactions on Communications},
title={On the BER Performance of Hierarchical M-QAM Constellations with Diversity and Imperfect Channel Estimation},
year={2007},
month={October},
volume={55},
number={10},
pages={1852-1856},
ISSN={0090-6778}
}