Angle of Arrival Measurements Using RF Carrier Synchronization and Phase Alignment Methods
First Claim
1. A method for determining an angle of arrival of a received signal, comprising:
- generating a baseband information signal by mixing a received signal with a local oscillator (LO) signal having an LO frequency, the received signal being an in-phase signal and quadrature signal uncorrelated with each other and derived from different input data sets;
obtaining baseband signal samples of the baseband information signal having an in-phase signal sample and a quadrature signal sample;
determining a transmitter phase offset based on an estimated correlation between the in-phase signal samples and the quadrature signal samples;
performing a plurality of phase measurements using a plurality of antennas to obtain a plurality of phase measurements;
correcting the plurality of phase measurements based on the transmitter phase offset to produce a plurality of corrected phase measurement; and
calculating an angle of arrival of the received signal based on the difference between the plurality of corrected phase measurements.
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Accused Products
Abstract
A method for determining an angle of arrival (AOA) of a received signal is disclosed, comprising: generating a baseband information signal by mixing a received signal with a local oscillator (LO) signal, the received signal being an in-phase signal and quadrature signal uncorrelated with each other and derived from different input data sets; obtaining baseband signal samples of the baseband information signal having an in-phase signal sample and a quadrature signal sample; determining a transmitter phase offset based on an estimated correlation between the in-phase signal samples and the quadrature signal samples; performing a plurality of phase measurements using a plurality of antennas to obtain a plurality of phase measurements; correcting the plurality of phase measurements based on the transmitter phase offset to produce a plurality of corrected phase measurement; and calculating an AOA of the received signal based on the difference between the plurality of corrected phase measurements.
26 Citations
26 Claims
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1. A method for determining an angle of arrival of a received signal, comprising:
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generating a baseband information signal by mixing a received signal with a local oscillator (LO) signal having an LO frequency, the received signal being an in-phase signal and quadrature signal uncorrelated with each other and derived from different input data sets; obtaining baseband signal samples of the baseband information signal having an in-phase signal sample and a quadrature signal sample; determining a transmitter phase offset based on an estimated correlation between the in-phase signal samples and the quadrature signal samples; performing a plurality of phase measurements using a plurality of antennas to obtain a plurality of phase measurements; correcting the plurality of phase measurements based on the transmitter phase offset to produce a plurality of corrected phase measurement; and calculating an angle of arrival of the received signal based on the difference between the plurality of corrected phase measurements.
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2. A method for determining an angle of arrival of a received signal, comprising:
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determining a phase offset of a mobile transmitter relative to an oscillator in a radio frequency (RF) transceiver; receiving a first signal from the mobile transmitter via a first antenna in the RF transceiver; receiving a second signal from the mobile transmitter via the first antenna, the second signal being received after reception of the first signal; comparing the first and the second signal to determine a delay; subtracting the phase offset of the mobile transmitter from the delay to obtain a position-dependent delay component; and determining an angle of arrival based on the position-dependent delay component.
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3. A method for performing angle of arrival measurements using a synchronized radio transceiver, comprising:
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synchronizing a carrier frequency of a receiver and a transmitter; measuring, at the receiver, a first measured signal phase for a signal transmitted by the transmitter at a first antenna at a first time; measuring, at the receiver, a second measured signal phase for the signal received at a second antenna at a second time; and calculating an angle of arrival based on a difference of the first and the second measured signal phase and on a physical distance between the first antenna and the second antenna, wherein the first antenna and the second antenna are coupled to the receiver. - View Dependent Claims (4, 5, 6, 7, 12, 13)
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8. A method for determining an angle of arrival of a received signal, comprising:
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generating a baseband information signal by mixing a received signal with a local oscillator (LO) signal having an LO frequency, the received signal being an in-phase signal and quadrature signal uncorrelated with each other and derived from different input data sets; obtaining baseband signal samples of the baseband information signal having an in-phase signal sample and a quadrature signal sample; determining a transmitter frequency offset based on an estimated correlation between the in-phase signal samples and the quadrature signal samples; performing a first phase measurement for the received signal using a single antenna to obtain a first phase measurement in a first plane; subsequently performing a second phase measurement for the received signal using a second antenna in the first plane; correcting the second phase measurement based on the transmitter frequency offset to produce a second corrected phase measurement; and calculating an angle of arrival in the first plane based on the difference between the second and first corrected phase measurements. - View Dependent Claims (9, 10)
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11. An antenna configuration for a radio frequency (RF) transceiver, comprising:
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a first antenna on a flat plane; a second antenna on the flat plane at a first distance from the first antenna along a first axis; a third antenna on the flat plane at a second distance from the first antenna along a second axis perpendicular to the first axis; a fourth antenna on the flat plane at a first distance from the second antenna along the first axis and at the second distance from the third antenna along the second axis; a single pole switch having a first throw connected to the first antenna, a second throw connected to the second antenna, a third throw connected to the third antenna, and a fourth throw connected to the fourth antenna; and a radio transceiver coupled to an output of the single pole switch, wherein the first, second, third, and fourth antennas are circularly polarized corner truncated patch antennas, thereby enabling the RF transceiver to perform sequential phase or time measurements for calculating angle of arrival.
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14. A radio frequency (RF) transceiver, comprising:
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a plurality of patch antennas on a first circuit board plane; a switching means on a second circuit board plane coupled to the plurality of patch antennas by vias; a radio frequency (RF) transceiver coupled to the switching means; and a processor coupled to the RF transceiver, wherein the processor is configured to operate the switching means to select a particular coupling of the plurality of patch antennas to the RF transceiver, and to perform a sequential series of phase measurements using the particular coupling of the plurality of patch antennas, and to calculate an angle of arrival, and wherein the processor is configured to calculate the angle of arrival by measuring a first phase measurement for a received signal for a first plane, subsequently measuring a second phase measurement for the received signal for the first plane, correcting the second phase measurement based on the measured frequency offset and initial phase of the received signal to produce a second corrected phase measurement, and calculating the angle of arrival in the first plane based on the difference between the second corrected and first phase measurements. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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Specification