Estimating Propagation Parameters using a Modified EM Algorithm for Mobile Location Estimation

Recently, mobile location estimation is drawing considerable attention in the field of wireless communications. Among different mobile location estimation methods, the one which estimates the location of mobile stations with reference to the wave propagation model is drawing much attention on the grounds that it is applicable to different kinds of cellular network. However, the signal propagation models require estimation of propagation parameters. We have revised the existing EM algorithm which is designed for signal propagation models. We have classified the EM algorithm into two cases — Sufficient Data Collection and Insufficient Data Collection. We experimented our modified EM algorithm with 192,177 sets of real life data collected from a major mobile phone operator of Hong Kong. Results show that the modified EM algorithm improves the existing parameters estimation algorithm in terms of estimation accuracy, stability in different types of landscapes.