@conference {GappmairCNSDSP08, title = {ML and EM Algorithm for non-data-aided SNR Estimation of Linearly Modulated Signals}, booktitle = {International Symposium on Communication Systems, Networks and Signal Processing (CNSDSP)}, year = {2008}, pages = {530-534}, keywords = {EM, ML, SNR estimation}, author = {Wilfried Gappmair and R. L{\'o}pez-Valcarce and C. Mosquera} }