Wireless Time Synchronization for Multi-Static Sensing in JCAS Systems

Abstract

Joint communication and sensing has been widely identified as a key technology, integrating sensing capabilities in future wireless communication systems. While single-node sensing is challenging due to full-duplex requirement, multistatic sensing not only exploits the existing communication infrastructure but also provides better coverage and improved detection accuracy. However, stringent requirements of time and frequency synchronization are needed to ensure spatial consistency of sensing measurements across nodes. We propose a technique to compensate time offsets between the transmitter and the receiver nodes by using asynchronous sensing results from at least two receiver nodes. It does not require assistance such as angle-of-departure, line-of-sight between transmitter and receiver, or a reference target. Simulation results validate the effectiveness of the proposed technique by demonstrating an accuracy of about 1 ns when employing an OFDM waveform with a bandwidth of 586 MHz.