5G PRS-Based Sensing: A Sensing Reference Signal Approach for Joint Sensing and Communication System

TL;DR

This paper explores using 5G PRS signals for radar sensing, enabling joint sensing, communication, and positioning, with improved accuracy and compatibility with existing mobile systems.

Contribution

It introduces a PRS-based radar sensing scheme, analyzes its performance, and proposes methods to enhance velocity estimation accuracy, advancing joint sensing and communication technology.

Findings

PRS-based sensing outperforms other pilot signals in radar detection

The proposed method improves velocity estimation accuracy using multiple frames

CRLB analysis confirms the theoretical bounds of estimation performance

Abstract

The emerging joint sensing and communication (JSC) technology is expected to support new applications and services, such as autonomous driving and extended reality (XR), in the future wireless communication systems. Pilot (or reference) signals in wireless communications usually have good passive detection performance, strong anti-noise capability and good auto-correlation characteristics, hence they bear the potential for applying in radar sensing. In this paper, we investigate how to apply the positioning reference signal (PRS) of the 5th generation (5G) mobile communications in radar sensing. This approach has the unique benefit of compatibility with the most advanced mobile communication system available so far. Thus, the PRS can be regarded as a sensing reference signal to simultaneously realize the functions of radar sensing, communication and positioning in a convenient manner. Firstly, we propose a PRS based radar sensing scheme and analyze its range and velocity estimation performance, based on which we propose a method that improves the accuracy of velocity estimation by using multiple frames. Furthermore, the Cramer-Rao lower bound (CRLB) of the range and velocity estimation for PRS based radar sensing and the CRLB of the range estimation for PRS based positioning are derived. Our analysis and simulation results demonstrate the feasibility and superiority of PRS over other pilot signals in radar sensing. Finally, some suggestions for the future 5G-Advanced and 6th generation (6G) frame structure design containing the sensing reference signal are derived based on our study.