Uplink Joint Positioning and Synchronization in Cell-Free Deployments with Radio Stripes

TL;DR

This paper explores how radio stripes can enable joint positioning and synchronization in cell-free wireless networks, providing theoretical analysis and simulation results that demonstrate promising performance and benefits of phase information exploitation.

Contribution

It introduces a joint estimation framework for position and synchronization using radio stripes, with theoretical bounds and analysis of phase exploitation benefits.

Findings

Promising positioning accuracy in cell-free architectures with radio stripes.

Significant benefits from exploiting carrier phase information.

Theoretical bounds indicate potential for high-precision synchronization.

Abstract

Radio stripes (RSs) is an emerging technology in beyond 5G and 6G wireless networks to support the deployment of cell-free architectures. In this paper, we investigate the potential use of RSs to enable joint positioning and synchronization in the uplink channel at sub-6 GHz bands. The considered scenario consists of a single-antenna user equipment (UE) that communicates with a network of multiple-antenna RSs distributed over a wide area. The UE is assumed to be unsynchronized to the RSs network, while individual RSs are time- and phase-synchronized. We formulate the problem of joint estimation of position, clock offset, and phase offset of the UE and derive the corresponding maximum-likelihood (ML) estimator, both with and without exploiting carrier phase information. To gain fundamental insights into the achievable performance, we also conduct a Fisher information analysis and inspect the theoretical lower bounds numerically. Simulation results demonstrate that promising positioning and synchronization performance can be obtained in cell-free architectures supported by RSs, revealing at the same time the benefits of carrier phase exploitation through phase-synchronized RSs.