Performance Bounds for Velocity Estimation with Large Antenna Arrays

TL;DR

This paper derives analytical bounds for velocity estimation using large antenna arrays in near-field conditions, highlighting how system parameters influence sensing performance in future 6G networks.

Contribution

It provides the first analytical performance bounds for both radial and transverse velocity components in near-field scenarios with large aperture arrays.

Findings

Velocity bounds depend on array size and geometry.

Near-field effects enable transverse velocity estimation.

Performance insights differ from far-field assumptions.

Abstract

Joint communication and sensing (JCS) is envisioned as an enabler of future 6G networks. One of the key features of these networks will be the use of extremely large aperture arrays (ELAAs) and high operating frequencies, which will result in significant near-field propagation effects. This unique property can be harnessed to improve sensing capabilities. In this paper, we focus on velocity sensing, as using ELAAs allows the estimation of not just the radial component but also the transverse component. We derive analytical performance bounds for both velocity components, demonstrating how they are affected by the different system parameters and geometries. These insights offer a foundational understanding of how near-field effects play in velocity sensing differently from the far field and from position estimate.