An investigation of min-max method problems for RSSI-based indoor localization: Theoretical and experimental studies

Abstract

A study of limitations of a min-max or a bounding-box method for received signal strength indicator (RSSI)-based indoor localization is introduced in this paper. The main goal of our study is to clearly understand how the widely used min-max method determines an unknown target position, and to investigate its significant limitations. For this purpose, we provide both theoretical and experimental studies. The theoretical study first gives an understanding of min-max theoretical limitations, while an experimental study then reveals more limitations. Experiments were done in an indoor environment, a laboratory room, where we employed an LPC2103F with a CC2500 RF module as a wireless node. Our results indicate that the min-max method can be efficiently used to estimate an unknown target’s position. However, such a method has limitations in several cases. First, it produces a significantly high estimation error when the unknown target is located outside an internal zone, the area within reference node positions. Second, fluctuations of measured RSSI signals in an obstacle environment is a major problem that produces significantly more estimation errors. Various effects in this case are detailed in the paper. Our information will be useful to develop more efficient min-max methods.

Keywords

• rssi
• bounding-box
• localization
• theoretical study
• experiment