CPC H04W 4/029 (2018.02) [G01S 5/021 (2013.01); G01S 5/0284 (2013.01); G01S 5/10 (2013.01); H04L 5/0007 (2013.01); H04L 5/0051 (2013.01); H04L 5/0053 (2013.01); H04W 56/001 (2013.01); H04W 64/00 (2013.01)] | 20 Claims |
1. A method for calculating a location of a user device comprising:
for each transceiver in a set of transceivers:
accessing a time-of-arrival of a multicarrier uplink signal, transmitted from the user device, at the transceiver, the time-of-arrival calculated by:
receiving the multicarrier uplink signal:
comprising a subcarrier uplink signal for each subcarrier frequency in a set of subcarrier frequencies;
for each subcarrier frequency in the set of subcarrier frequencies:
calculating a phase difference between each subcarrier uplink signal and a corresponding subcarrier reference signal;
calculating a phase offset based on the subcarrier frequency and a calibration function for the transceiver;
generating an adjusted phase difference in a set of adjusted phase differences, for the multicarrier uplink signal based on the phase difference and the phase offset; and
calculating the time-of-arrival of the multicarrier uplink signal based on the set of adjusted phase differences for the multicarrier uplink signal; and
calculating a set of time-differences-of-arrival based on the time-of-arrival of the multicarrier uplink signal; and
calculating an uplink location estimate of the user device based on the set of time-differences-of-arrival and a location of each transceiver in the set of transceivers.
|