Simulation Model of 5G NR Network Positioning Technology with Meter Accuracy. Part 1.PRS Signals Configuration
Authors: Fokin G. 
Published: July 2022

The evolution of 1G–4G mobile communication networks (MCNs) has shown that network positioning has traditionally been considered as one of the additional features in the process of standardization, construction, and operation of networks, which was in demand when the signals of global navigation satellite systems were unavailable. MCNs were used to determine location mainly in the interests of emergency services and law enforcement. However, the developed MCN infrastructure opened up wide opportunities for determining the location of devices. Therefore, in the process of evolution, starting with analog 1G MCNs, positioning methods were also improved. Digital 2G GSM MCNs contributed to the development of network positioning with an accuracy of tens or hundreds of meters at the request of the regulator. The globalization of MCNs is associated with the 3rd Generation Partnership Project (3GPP) for the standardization of 3G universal mobile telecommunications systems. Since the 3G generation, in the process of MCN standardization, the 3GPP specifications began to impose requirements for network location determination. This trend was continued in 4G LTE MCNs and further developed in 5G networks. For 5G networks, in the latest 3GPP specifications, in contrast to MCNs of previous generations, the requirements for positioning accuracy up to one meter are formalized for the first time. At the same time, in addition to the traditional 2G–4G cases of emergency calls, positioning scenarios are presented in public communication networks, both for subscribers and devices: location-based service, positioning in industry and healthcare, traffic control, rail and sea transportation, as well as positioning using unmanned aerial vehicles. To solve the ambitious task of positioning with an accuracy of up to one meter, which is approximately an order of magnitude less than in previous MCN generations, 5G networks at the radio interface level use special positioning reference signals (PRS), first proposed in 4G LTE MCNs. The new 5G NR radio interface, unlike the 4G LTE MCNs of previous generations, allows the use of an order of magnitude wider frequency bands in the millimeter-wave range (mmWave), which allows achieving meter positioning accuracy. From the point of view of collecting and processing primary measurements, the positioning accuracy is determined, first of all, by the signals used. Using the built-in functions of the 5G Toolbox extension package of the special Matlab software allows visualizing the PRS signal configuration procedures in the time-frequency domain of the 5G NR radio interface. The first part of the study considers 5G NR network positioning technology modeling and formalizes the PRS signal configuration procedures used to collect primary measurements. Simulation modeling of procedures for secondary processing of primary measurements with the resulting estimate of the coordinates of 5G NR devices is the subject of research in the second part. The result of this work is the substantiation of the problem of achieving meter accuracy of device positioning in networks of the fifth and subsequent generations, as well as setting the task of the secondary processing of primary measurements using configured PRS signals.