Effect Of User Azimuth Direction On Rss Based Range Estimation Accuracy
Dorathy O Abonyi
Department of Electrical and Electronic Engineering, Enugu State University of Science and Technology, Enugu, Nigeria
Keywords: Antenna array, Angle-of-arrival, RSSI, Algorithm
Abstract
Localization of radio unit in an unknown position can be widely categorized as range-free or range-based. In range based
approach, calculation of the distance of radio unit from a reference point is required. This can be achieved using GPS, time dependent or RSS based approaches. User privacy is not guaranteed with GPS and time dependent approach is hard to achieve in practice. RSS based approach is getting popular because it provides anonymous data and it is readily available in most radio units. Accuracy of RSS based approach is a serious problem because of its strong dependent on environment of propagation. This paper presents a simple RSS based range estimation model and investigates the effect of azimuth user position on the range estimation accuracy. MATLAB simulation result show that error in range estimation is highly depended on user azimuth position from the base station. Simulation with twenty sample users gave a range estimation error within the range of ±1° for users on broadside and end-fire positions. This error was observed to increase as users move away from beam peaks. Users located left and right of broadside encountered high bound of error showing that levels of error experienced in RSS based range estimation is user azimuth position dependent.