System and methods for improving secure phase-based positioning accuracy

An apparatus comprising:

• a main transceiver configured to be coupled to a first antenna to receive a radio frequency (RF) signal during a plurality of time intervals to determine a plurality of first phase values of the RF signal using a first local oscillator of the main transceiver, each of the plurality of first phase values corresponding to one of the plurality of time intervals;
• an auxiliary receiver configured to be coupled to a plurality of auxiliary antennas to receive the RF signal during the plurality of time intervals to determine a plurality of second phase values of the RF signal using a second local oscillator of the auxiliary receiver, each of the plurality of second phase values corresponding to the RF signal received though one of the plurality of auxiliary antennas during one of the plurality of time intervals;
• a regulator configured to determine an oscillator phase offset between the first local oscillator of the main transceiver and the second local oscillator of the auxiliary receiver;
• and
• a direction estimator configured to estimate a position associated with a source of the RF signal based on the plurality of first phase values of the RF signal and the plurality of second phase values of the RF signal, wherein the direction estimator is configured to compensate for the oscillator phase offset to estimate the position.

A wireless device comprising:

• an antenna array including one or more main antennas and a plurality of auxiliary antennas;
• a first receiver coupled to a first antenna of the main antennas and to a first local oscillator over a plurality of time intervals to receive a radio frequency (RF) signal from the first antenna for down-conversion using the first local oscillator to determine a plurality of first phase values of the RF signal, each of the plurality of first phase values corresponding to one of the plurality of time intervals;
• a coupling circuit configured to switch one of main antennas or one of the plurality of auxiliary antennas to an auxiliary receive path;
• a second receiver coupled to the auxiliary receive path and to a second local oscillator during the plurality of time intervals to receive the RF signal from the plurality of auxiliary antennas for down-conversion using the second local oscillator to determine a plurality of second phase values of the RF signal, each of the plurality of second phase values corresponding to the RF signal received though one of the plurality of auxiliary antennas during one of the plurality of time intervals;
• a regulator configured to determine an oscillator phase offset between the first local oscillator and the second local oscillator;
• and
• a processor configured to compensate for an effect of the oscillator phase offset on the plurality of first phase values of the RF signal and on the plurality of second phase values of the RF signal to estimate a position associated with a source of the RF signal.