Device Positioning Scheme in LTE Network with D2D Signal

Abstract

In this paper, we study a positioning scheme with device-to-device (D2D) communications in LTE networks. Recently, there has been increasing interest in a positioning technique to support location-based services (LBS). Various positioning techniques are supported in LTE networks such as assisted global navigation satellite system (A-GNSS) and observed time difference of arrival (OTDOA). With emerge of D2D communications in LTE networks, positioning technique based on D2D communication attracts growing attention. A-GNSS provides more accurate positioning service than other positioning technique but it is not available in indoor or urban environments. The accuracy of OTDOA and centroid positioning changes due to the surrounding environment, i.e., position of base stations, distances to base stations, and density of neighbor D2D devices. We derive the mathematical analysis to predict the positioning accuracy of centroid positioning based on the gathered information about surrounding environments. Based on the analysis, hybrid positioning scheme, which exploits a strength of OTDOA and centroid positioning is proposed. The proposed hybrid positioning scheme dynamically selects the positioning scheme which is expected to have better performance in accordance with collected information. Numerical results show that the proposed hybrid positioning scheme achieves better performance than conventional positioning schemes for various environments.