US 11,960,018 B2
Receiver design for doppler positioning with low earth orbit satellites and differential carrier phase measurements
Zak Kassas, Irvine, CA (US); Joe Khalife, Irvine, CA (US); and Ali Abdallah, Irvine, CA (US)
Assigned to The Regents of the University of California, Oakland, CA (US)
Appl. No. 17/604,154
Filed by The Regents of the University of California, Oakland, CA (US)
PCT Filed Apr. 15, 2020, PCT No. PCT/US2020/028281
§ 371(c)(1), (2) Date Oct. 15, 2021,
PCT Pub. No. WO2020/214680, PCT Pub. Date Oct. 22, 2020.
Claims priority of provisional application 62/934,493, filed on Nov. 12, 2019.
Claims priority of provisional application 62/834,317, filed on Apr. 15, 2019.
Prior Publication US 2022/0171013 A1, Jun. 2, 2022
Int. Cl. H04W 64/00 (2009.01); G01S 5/00 (2006.01); G01S 5/02 (2010.01); H04W 4/02 (2018.01)
CPC G01S 5/0284 (2013.01) [G01S 5/009 (2013.01); G01S 5/0246 (2020.05)] 20 Claims
OG exemplary drawing
 
1. A method for determining position based on low Earth orbit (LEO) satellite signals, the method comprising:
receiving, by a device, one or more low earth orbit (LEO) satellite signals, wherein the LEO satellite signals include direct quadrature phase shift keying (QPSK) signals;
performing, by the device, a Doppler frequency measurement for the quadrature phase shift keying (QPSK) signals for each downlink channel received, wherein the Doppler frequency measurement includes
filtering each received downlink channel, and
performing a channel tracking operation for each filtered downlink channel, the channel tracking operation including an independent phase-lock loop to track each filtered downlink signal, wherein each phase-lock loop determines a Doppler shift measurement; and
performing, by the device, a navigation filter operation to determine clock drift based on each Doppler shift measurement from each channel tracking loop; and
determining, by the device, a position of the device, wherein the device determines position based on clock drift determined by the navigation filter operation and tracking data for each LEO satellite signal source.