  In this work, we propose a novel approach for high accuracy user localization
by merging tools from both millimeter wave (mmWave) imaging and communications.
The key idea of the proposed solution is to leverage mmWave imaging to
construct a high-resolution 3D image of the line-of-sight (LOS) and
non-line-of-sight (NLOS) objects in the environment at one antenna array. Then,
uplink pilot signaling with the user is used to estimate the angle-of-arrival
and time-of-arrival of the dominant channel paths. By projecting the AoA and
ToA information on the 3D mmWave images of the environment, the proposed
solution can locate the user with a sub-centimeter accuracy. This approach has
several gains. First, it allows accurate simultaneous localization and mapping
(SLAM) from a single standpoint, i.e., using only one antenna array. Second, it
does not require any prior knowledge of the surrounding environment. Third, it
can locate NLOS users, even if their signals experience more than one
reflection and without requiring an antenna array at the user. The approach is
evaluated using a hardware setup and its ability to provide sub-centimeter
localization accuracy is shown.
