Localization of Mobile Stations from ONE Base Station in GSM Systems

Abstract

Localization of Mobile Stations (MS) in cellular communication systems is an interesting area of research, where large number of techniques is used to reduce the errors in estimating the position of the MS. The MUSIC DOA estimation algorithm (Multiple Signal Classification (MUSIC) with Direction of Arrival (DOA) algorithm) using only ONE Base Station (BS) with the assistant of retrieving the Timing Advance (TA) from the Base Station (BS) is a promising technique. In the 2D DOA estimation algorithm, two or more BS’s are needed to solve for the MS coordinates. In this approach, only one BS is needed to assign the direction of the MS, where the distance can be calculated from the TA reading. Retrieving the TA results in distances between an integer value between 0 – 63 multiplied by 554 m. the location of the MS is lied between TA and (TA+1) multiplied by 554 m as a radius with the centre being the position of the BS. Since the difference between the highest and the lowest values of the distances to the BS is 554 m, thus by averaging the result of the estimation process the location will be in the middle of the distance. Ideally, the error in estimating the distance will be between 0 – 277 m above or below the average value. However, the error is verified to be more or less due to the error in estimating the DOA.