Fingerprint-Spectrum-Based Synchronization in Asynchronous Perceptive Mobile Networks
Xiao-Yang Wang, Shaoshi Yang, Mingyang Chen, Christos Masouros · 2024
Asynchronous radio transceivers introduce significant range and velocity ambiguity, posing challenges for accurate positioning and velocity estimation in passive sensing perceptive mobile networks (PMNs). To address this issue, we propose the Cross-Multipath Cross-Correlation (CMCC) algorithm, a joint carrier frequency offset (CFO) and time offset (TO) estimation algorithm that supports passive sensing in both non-line-of-sight (NLOS) and line-of-sight (LOS) environments. The CMCC algorithm treats the delay-Doppler spectrum of signals reflected from static objects as an environment-specific "fingerprint spectrum" that exhibits a cyclic shift property as the CFO and/or TO change. By analyzing the number of cyclic shifts, CMCC efficiently estimates both CFO and TO. Additionally, we provide a simplified version of CMCC to reduce computational complexity. Simulation results demonstrate the performance advantages of our algorithms across various configurations.