Direction estimation for cellular enhanced cell-ID positioning using multiple sector observations

In this paper, we propose a method that estimates the direction of a set of User Equipment (UE) more accurately for Enhanced Cell-ID (ECID) positioning of a cellular system than the conventional sector based positioning method. The proposed method estimates the direction of the UE using the number of observations in reception sectors. The average received power ratio of the reception sectors is calculated using the observation results of the sector reception situation and antenna patterns of the reception sector are used to estimate the UE direction. This enables estimation of the direction from simply obtained information. The evaluation results of the proposed method are presented based on computer simulations of the direction accuracy and positioning accuracy. The improvement in the direction accuracy compared to the conventional method is approximately 65% (11°) in a Rayleigh fading environment when the number of observations is 10 and the width of sector is 60°. Round Trip Time (RTT) positioning accuracy is improved by approximately 50% (150 m) using the proposed method when the error in the RTT measurement is 156 m and the cell spacing is 4 km.