US 12,298,411 B2
Determining multipath in a positioning system
Rayman Wai Pon, Cupertino, CA (US); and Pranav Iyengar, San Diego, CA (US)
Assigned to QUALCOMM Incorporated, San Diego, CA (US)
Filed by QUALCOMM Incorporated, San Diego, CA (US)
Filed on Apr. 4, 2024, as Appl. No. 18/627,246.
Application 18/627,246 is a continuation of application No. 17/486,366, filed on Sep. 27, 2021, granted, now 12,019,167.
Prior Publication US 2024/0272305 A1, Aug. 15, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. G01S 19/22 (2010.01); G01S 19/42 (2010.01); G01S 19/47 (2010.01)
CPC G01S 19/22 (2013.01) [G01S 19/428 (2013.01); G01S 19/47 (2013.01)] 27 Claims
OG exemplary drawing
 
1. A method for multipath estimation at a mobile device, the method comprising:
receiving, using one or more antennas at the mobile device, one or more signals from a Global Navigation Satellite System (GNSS) satellite, the one or more signals comprising a right-handed circularly polarized (RHCP) signal and a left-handed circularly polarized (LHCP) signal, wherein the RHCP signal and the LHCP signal are received over a single signal path from an antenna subsystem of the mobile device;
generating a first indication of signal strength from the RHCP signal;
generating a second indication of signal strength from the LHCP signal;
determining an indication of multipath reflection along a path of signal propagation between the GNSS satellite and the mobile device based on the first indication and the second indication; and
determining a presence of signal spoofing source associated with the one or more signals received from the GNSS satellite based on the first indication and polarization characteristics of the RHCP signal, the second indication and polarization characteristics of the LHCP signal, and a multipath characteristic associated with the one or more signals received from the GNSS satellite, wherein the multipath characteristic comprises a relationship between the first indication of signal strength and the second indication of signal strength, and wherein the presence of a spoofing signal source is determined by evaluating the polarization characteristics of the RHCP signal, the polarization characteristics of the LHCP signal, and the multipath characteristic associated with the one or more signals received from the GNSS satellite.