Radio frequency ranging using phase difference
First Claim
1. A radio system, comprising:
- a first radio unit, configured to transmit a first radio signal; and
a second radio unit, configured to receive the first radio signal, adjust a reference clock signal of the second radio unit based on the first radio signal, and transmit a second radio signal generated based on the adjusted reference clock signal; and
a data processing unit configured to determine a distance between the first radio unit and the second radio unit based on a phase difference between the first radio signal and the second radio signal received at the first radio unit,wherein;
the first radio signal has a first frequency,the first radio unit is further configured to transmit a third radio signal that has a second frequency,the second radio unit is further configured to receive the third radio signal, adjust the reference clock signal of the second radio unit based on the third radio signal, and transmit a fourth radio signal generated based on the reference clock signal adjusted based on the third radio signal, andthe data processing unit is configured to determine the distance between the first radio unit and the second radio unit further based on a phase difference between the third signal transmitted by the first radio unit and the fourth signal received at the first radio unit.
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Accused Products
Abstract
Embodiments of the present disclosure describe mechanisms for radio frequency (RF) ranging between pairs of radio units based on radio signals exchanged between units. An exemplary radio system may include a first radio unit, configured to transmit a first radio signal, and a second radio unit configured to receive the first radio signal, adjust a reference clock signal of the second radio unit based on the first radio signal, and transmit a second radio signal generated based on the adjusted reference clock signal. Such a radio system may further include a processing unit for determining a distance between the first and second radio units based on a phase difference between the first radio signal as transmitted by the first radio unit and the second radio signal as received at the first radio unit. Disclosed mechanisms may enable accurate RF ranging using low-cost, low-power radio units.
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Citations
21 Claims
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1. A radio system, comprising:
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a first radio unit, configured to transmit a first radio signal; and a second radio unit, configured to receive the first radio signal, adjust a reference clock signal of the second radio unit based on the first radio signal, and transmit a second radio signal generated based on the adjusted reference clock signal; and a data processing unit configured to determine a distance between the first radio unit and the second radio unit based on a phase difference between the first radio signal and the second radio signal received at the first radio unit, wherein; the first radio signal has a first frequency, the first radio unit is further configured to transmit a third radio signal that has a second frequency, the second radio unit is further configured to receive the third radio signal, adjust the reference clock signal of the second radio unit based on the third radio signal, and transmit a fourth radio signal generated based on the reference clock signal adjusted based on the third radio signal, and the data processing unit is configured to determine the distance between the first radio unit and the second radio unit further based on a phase difference between the third signal transmitted by the first radio unit and the fourth signal received at the first radio unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A radio unit, comprising:
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means for receiving a first radio signal transmitted by a further radio unit; means for generating a reference clock signal based on which the radio unit is configured to transmit radio signals; means for adjusting the reference clock signal based on the first radio signal; and means for transmitting a second radio signal generated based on the adjusted reference clock signal, wherein; the second radio signal is configured to enable determination of a distance between the radio unit and the further radio unit based on a phase difference between the first radio signal transmitted by the further radio unit and the second radio signal transmitted by the radio unit as received at the further radio unit, said first radio signal is one of a plurality of first radio signals, each of the first radio signals having a different frequency, the means for adjusting the reference clock signal based on the first radio signal is configured to adjust the reference clock signal based on the first radio signal for each of the plurality of first radio signals, and the means for transmitting the second radio signal is configured to transmit the second radio signal generated based on the adjusted reference clock signal for each of the plurality of first radio signals, and the plurality of first radio signals include radio signals at frequency steps of between 10 kilohertz and 10 megahertz. - View Dependent Claims (12, 13, 14, 15)
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16. A radio system, comprising:
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a first radio unit; a second radio unit; and a data processing unit, wherein the first radio unit is configured to transmit and receive signals at a plurality of different frequencies, and, for each frequency of the plurality of different frequencies; the first radio unit is configured to transmit a first radio signal at the frequency, the second radio unit is configured to; adjust a frequency of the reference clock signal of the second radio unit to be equal to the frequency of the first radio signal, adjust a phase of the frequency-adjusted reference clock signal of the second radio unit based on a phase of the first radio signal as received by the second unit, and transmit a second radio signal generated based on the frequency- and phase-adjusted reference clock signal of the second radio unit, and the data processing unit is configured to determine a phase difference between a phase of the first radio signal as transmitted by the first radio unit and a phase of the second radio signal as received by the first radio unit, and wherein the data processing unit is configured to determine a distance between the first radio unit and the second radio unit based on the phase difference determined for the each frequency of the plurality of different frequencies. - View Dependent Claims (17)
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18. A radio unit, comprising:
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a receiver configure to receive a first radio signal transmitted by a further radio unit; a data processing unit configured to adjust a reference clock signal of the radio unit based on the first radio signal; and a transmitter configured to transmit a second radio signal generated based on the reference clock signal adjusted based on the first radio signal, wherein; the second radio signal is configured to enable determination of a distance between the radio unit and the further radio unit based on a phase difference between the first radio signal transmitted by the further radio unit and the second radio signal as received at the further radio unit, the first radio signal has a first frequency, the receiver is further configure to receive a third radio signal transmitted by the further radio unit, the third radio signal having a second frequency, different from the first frequency, the data processing unit is further for adjusting the reference clock signal of the radio unit based on the third radio signal, the transmitter is further for transmitting a fourth radio signal generated based on the reference clock signal adjusted based on the third radio signal, and the fourth radio signal is configured to further enable determination of the distance between the radio unit and the further radio unit based on a phase difference between the third signal transmitted by the further radio unit and the fourth signal received at the further radio unit. - View Dependent Claims (19, 20, 21)
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Specification