Joint Delay and Phase Discriminator Based on ESPRIT for 5G NR Positioning

A joint delay and phase discriminator based on the ESPRIT algorithm is proposed for positioning with the fifth generation (5G) New Radio (NR) downlink cellular signals. Since ESPRIT requires knowledge of the number of paths of the radio channel to operate, the proposed discriminator is coupled and studied with two channel order estimators: minimum descriptive length (MDL) and efficient channel order determination (ECOD). To mitigate the delay and phase outliers appearing when the MDL overestimates the channel order, a path selection criterion based on the signal-to-noise ratio (SNR) of the path is proposed. The ESPRIT discriminator is evaluated in terms of the distribution of the estimated channel order, and the delay and phase errors in the absence and presence of multipath. It is observed that the path selection criterion makes the MDL suitable for positioning as no delay and phase outliers are produced. In the presence of multipath, the ESPRIT discriminator achieves lower mean and root-mean-square delay and phase errors than the commonly used early-minus-late power (EMLP) and 2-argument arctangent (ATAN2) discriminators.