US 11,711,254 B2
Sub-nanosecond RF synchronization for MIMO software defined radio sensor networks
Mahta Moghaddam, Los Angeles, CA (US); Samuel M. Prager, Los Angeles, CA (US); and Mark S. Haynes, Pasadena, CA (US)
Assigned to University of Southern California, Los Angeles, CA (US)
Filed by UNIVERSITY OF SOUTHERN CALIFORNIA, Los Angeles, CA (US); and CALIFORNIA INSTITUTE OF TECHNOLOGY, Pasadena, CA (US)
Filed on Jan. 14, 2022, as Appl. No. 17/576,806.
Claims priority of provisional application 63/137,887, filed on Jan. 15, 2021.
Prior Publication US 2022/0239541 A1, Jul. 28, 2022
Int. Cl. H04L 27/26 (2006.01); H04B 1/00 (2006.01); H04W 56/00 (2009.01)
CPC H04L 27/2663 (2013.01) [H04B 1/0003 (2013.01); H04L 27/266 (2013.01); H04W 56/001 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for providing wireless clock synchronization of multiple devices, the method comprising:
performing coarse synchronization by synchronizing clocks of each of the multiple devices using an independent clock source; and
performing fine clock synchronization by:
measuring pair-wise radio frequency (RF) time of flight using baseband waveform samples of each of the multiple devices based on the clocks of each of the multiple devices; and
applying at least one of (i) a fractional delay and (ii) a phase correction to the baseband waveform samples to cause the baseband waveform samples to replicate equivalently synchronized sample clocks.