Comparison between least squares path loss estimation and averaging for handover algorithms

A comparative analysis is provided between two classes of linear handover algorithms; namely, the classical averaging of the instantaneous power level and the least squares estimate of the path loss parameters, for each radio link between the mobile station and surrounding base stations. For a given trip of the mobile station in a log-normal fading environment, the comparison, in terms of mean time between handovers and mean time between outages, is performed for different values of the mobile speed and shadow fading correlation distance. It is seen that in averaging-based algorithms the above performance measures cannot be maximized at the same time and an accurate trade-off is required in the choice of the averaging window, which is a function of the mobile speed. On the other hand, least squares methods assume to know the distances between the mobile and the surrounding base stations. However, they yield an improvement of both performance measures for longer estimation window lengths. Moreover, if the window is long enough, least square methods yield always better performance than averaging methods