US 12,407,593 B2
Wi-Fi based fine ranging using carrier phase information
Vishnu Vardhan Ratnam, Plano, TX (US); Bilal Sadiq, Plano, TX (US); Hao Chen, Allen, TX (US); Abhishek Sehgal, Frisco, TX (US); Boon Loong Ng, Plano, TX (US); and Jianzhong Zhang, Dallas, TX (US)
Assigned to Samsung Electronics Co., Ltd., Suwon-si (KR)
Filed by Samsung Electronics Co., Ltd., Suwon-si (KR)
Filed on Oct. 13, 2023, as Appl. No. 18/486,906.
Claims priority of provisional application 63/434,433, filed on Dec. 21, 2022.
Prior Publication US 2024/0223484 A1, Jul. 4, 2024
Int. Cl. H04L 43/0864 (2022.01); H04L 25/02 (2006.01); H04L 27/26 (2006.01); H04L 43/0829 (2022.01)
CPC H04L 43/0864 (2013.01) [H04L 25/0202 (2013.01); H04L 27/2659 (2013.01); H04L 27/266 (2013.01); H04L 43/0841 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
obtaining Wi-Fi channel state information (CSI) parameters measured at an anchor and a target device from Wi-Fi frames transmitted between the anchor and the target device, the CSI parameters comprising, for each of the anchor and the target device, frame transmission and reception times, a carrier phase of the CSI, a crystal offset factor, and a packet detection time error, wherein each crystal offset factor is estimated based on a carrier frequency offset (CFO) between the target device and the anchor;
determining a round trip time (RTT) estimate or a relative change in the RTT estimate as a function of the CSI parameters; and
estimating a range between the anchor and the target device as a function of the RTT estimate, or estimating a change in the range between the anchor and the target device as a function of the relative change in the RTT estimate.