Positioning precision analysis on 5G mmWave and sub-6G signals

With the persistent research and rapid commercialization of 5th generation mobile communication technology (5G), China has built one of the largest commercial 5G network. Suppliers of 5G equipment start to provide new positioning features based on 5G new radio (NR). It is highly probable that the high-precision positioning technology will be gradually commercialized in the next few years. Compared with 4G long term evolution (LTE), denser network deployments and wider transmission bandwidth of 5G can bring about a significant improvement in positioning accuracy. Hopefully, 5G positioning can mitigate coverage and accuracy problems of Global Navigation Satellite Systems (GNSS) in difficult environments such as indoor and urban canyons. This article describes the differences between 5G and 4G in the measurement domain. Then the precision of Sub-6G (FR1) and high frequency mm wave (FR2) ranging measurements with Cramér-Rao bound is assessed. Followed by the description of positioning algorithms, eleven scenarios are listed with typical simulation parameters based on 3GPP specifications and commercial network configurations. The simulation results show that the precision of network synchronization is the main factor affecting the positioning quality. If the time synchronization error is 50 ns, 5G positioning precision is over 10 m. A larger bandwidth can significantly improve the ranging precision of 5G signals if the time synchronization problem can be solved by ideal synchronization or double-differencing with positioning nodes near a user end. Under ideal conditions, 5G FR1 can achieve an accuracy of about 1 m, and FR2 can achieve an accuracy of 0.16 m.