Indoor positioning in 5G new radio: how it works, status quo of research, and the road ahead

In this paper, the architecture and mechanism of 5G New Radio indoor positioning schemes such as downlink time difference of arrival (DL-TDOA), uplink (UL) TDOA, multiple-cell round trip time (Multi-RTT), DL angle of departure, UL angle of arrival (AOA), and enhanced cell-ID, are comprehensively described. In addition, their performances are investigated under different channel bandwidths and conditions, and antenna configurations. Numerical results show the time-based schemes provide more benefit by wider bandwidth, while the angle-based schemes give gains by more antenna elements. Note that the Multi-RTT achieves the best accuracy with line-of-sight (LOS) conditions, while the UL-AOA does with non-LOS.