After robust connectivity, precise positioning is evolving into an innovative
component of 5G service offerings for industrial use-cases and verticals with
challenging indoor radio environments. In this direction, the 3GPP Rel-16
standard has been a tipping point in specifying critical innovations, followed
by enhancements in Rel-17+. In this article, we follow this path to elaborate
on the 5G positioning framework, measurements, and methods before shifting the
focus to carrier-phase (CP) measurements as a complementary measure for time-
and angular-based positioning methods toward achieving centimeter-level
accuracy. As this path is not without challenges, we discuss these and outline
potential solutions. As an example of solutions, we study how phase-continuous
reference signaling can counter noisy phase measurements using realistic
simulations in an indoor factory (InF) scenario.Comment: 5 figures, 1 table, under review for possible publication in IEEE
Communications Magazin