  3GPP air interface standards support meter-level position location of a user
in a cellular network. With wider bandwidths and narrow antenna beamwidths
available at mmWave frequencies, cellular networks now have the potential to
provide sub-meter position location for each user. In this work, we provide an
overview of 3GPP position location techniques that are designed for
line-of-sight propagation. We discuss additional measurements required in the
3GPP standard that enable multipath-based non-line-of-sight position location.
Further, we validate the concepts in this paper by using field data to test a
map-based position location algorithm in an indoor office environment which has
dimensions of 35 m by 65.5 m. We demonstrate how the fusion of angle of arrival
and time of flight information in concert with a 3-D map of the office provides
a mean accuracy of 5.72 cm at 28 GHz and 6.29 cm at 140 GHz, over 23 receiver
distances ranging from 4.2 m to 32.3 m, using a single base station in
line-of-sight and non-line-of-sight. We also conduct a theoretical analysis of
the typical error experienced in the map-based position location algorithm and
show that the complexity of the map-based algorithm is low enough to allow
real-time implementation.
