Hoang, Manh Kha, and Reinhold Haeb-Umbach. “Parameter Estimation and Classification of Censored Gaussian Data with Application to WiFi Indoor Positioning.”https://doi.org/10.1109/ICASSP.2013.6638353__In 38th International Conference on Acoustics, Speech, and Signal Processing (ICASSP 2013), 3721–25, 2013.https://doi.org/10.1109/ICASSP.2013.6638353 .