Error Analysis of the Distance and Distance Difference for SSSD-based Wireless Location: Part I-Theoretical Aspects

Mobile location services (MLS) in wireless networks continue to advance. The promise of new MLS is for a substantial part concentrated on location estimation. Depending on the distance and distance-difference estimated from the stationary signal-strength-difference (SSSD) measurements, the location of the mobile caller is provided by using the circular and hyperbolic algorithms respectively. However, its performance is limited because the accuracy of the distance and distance-difference are affected by two impairment factors: one factor is the SSSD measurement error and one factor is an error resulted from the detection of the reference distance, called the detection error. In part I of this paper, we present a systematical analysis for the reference distance detection and SSSD measurement errors, which gives a convincing argument that a larger error is possible to expect and exist in the distance and distance-difference for which can be corrected via the least square (LS). In part II, the theoretical findings were demonstrated with a commercial cellular wireless network measurement.