Radio Positioning with EM Processing of the Spherical Wavefront

TL;DR

This paper explores how EM processing of spherical wavefronts with large antenna arrays can enable accurate transmitter positioning in 5G systems, analyzing trade-offs and robustness to interference.

Contribution

It introduces a general EM processing model for various array configurations and evaluates positioning performance and complexity trade-offs in next-generation systems.

Findings

Positioning accuracy achievable with limited antenna arrays.

Trade-offs between system complexity and performance.

Robustness to interference from multiple sources.

Abstract

Next 5G and beyond applications have brought a tremendous interest towards array systems employing an extremely large number of antennas, so that the technology that might be in place for communication can be also exploited for positioning. In particular, in this paper we investigate the possibility to infer the position of an omnidirectional transmitter by retrieving the information from the incident spherical wavefront through its EM processing. Despite such a post-processing of the curvature wavefront has been mainly considered in the past at microwave and acoustic frequencies using extremely large antennas, it is of interest to explore the opportunities offered in the context of next 5G and beyond systems. Thus, differently from the state-of-the-art, here we first introduce a dedicated general model for different EM processing configurations, and successively we investigate the trade-off between the attainable positioning performance and the complexity offered by the different architectures, that might entail or not the use of a lens, that can be either reconfigurable or not. Indeed, we analyze also the effect of the interference, in order to evaluate the robustness of the considered system to the presence of multiple simultaneous transmitting sources. Results, obtained for different number of antennas, i.e., for different array apertures, confirm the possibility to achieve interesting positioning performance using a single antenna array with limited dimensions.