@article {ValcarceMosqueraTCOM08,
	title = {Cramer-Rao Lower Bound and EM Algorithm for Envelope-Based SNR Estimation of Nonconstant Modulus Constellations},
	journal = {IEEE Transactions on Communications},
	volume = {57},
	number = {6},
	year = {2009},
	month = {june},
	pages = {1622 - 1627},
	author = {Wilfried Gappmair and R. L{\'o}pez-Valcarce and C. Mosquera}
}
