Simulation and Analysis of Device Positioning in 5G Ultra-Dense Network.

Device positioning has generally been recognized as an important service of LTE Advanced pro and the upcoming fifth generation (5G) mobile communication. The Observed Time Difference of Arrival (OTDoA) technique that utilizes cellular signals for positioning is considered as a promising candidate technology capable of meeting users’ growing demands for high-precision and ubiquitous device positioning. The application of ultra-dense network (UDN) in 5G systems brings new opportunities and challenges to device positioning. However, existing researches mainly focus on the communication characteristics of UDN, while its positioning characteristics have not been analyzed thoroughly. In this study, a software simulation platform of OTDoA positioning in 5G UDN is first established based on the current 5G standards. Then, the performance of OTDoA technique in UDN and its influencing factors are comprehensively analyzed by heat map method over our simulation platform. The simulation results demonstrate that in 5G UDN, the unsatisfactory geometric distribution quality of base stations used for positioning and the non-line-of-sight (NLoS) propagation of cellular signals are the main factors that cause the performance degradation of OTDoA positioning. Moreover, based on the above analysis, we also provide some meaningful guidance for the development or improvement of OTDoA positioning technique used in 5G UDN.