High Accuracy Wireless Time Synchronization for Distributed Antenna Arrays

A method for high accuracy time synchronization of nodes in a distributed antenna array that achieves time alignment accuracy of less than 10 ps is demonstrated. This technique utilizes a two-step process, first performing coarse time synchronization using a conventional pulse-per-second-based time alignment to distribute a global timestamp on device startup, then performing a refinement process using a pulsed dual-tone waveform that is matched filtered and interpolated for fine delay estimation. This process is demonstrated experimentally using software-defined radio nodes separated by 1.2 m using a carrier of 5.8 GHz and a dual-tone waveform with 50 MHz bandwidth.