Localization algorithm performance in ultra low power active RFID based patient tracking

Indoor personnel localization research has generated a range of potential techniques and algorithms. However, these typically do not account for the influence of the user´s body upon the radio channel. In this paper an active RFID based patient tracking system is demonstrated and three localization algorithms are used to estimate the location of a user within a modern office building. It is shown that disregarding body effects reduces the accuracy of the algorithms´ location estimates and that body shadowing effects create a systematic position error that estimates the user´s location as closer to the RFID reader that the active tag has line of sight to.