Maintaining coordination following a wireless reset
First Claim
1. An electronic device, comprising:
- one or more antennas;
a clock circuit that is configured to provide a clock; and
an interface circuit communicatively coupled to the one or more antennas and the clock circuit, wherein the interface circuit is configured to;
receive, from the one or more antennas, packets associated with a second electronic device, wherein a given packet comprises a transmit time, based on a second clock in the second electronic device, when the second electronic device transmitted the given packet;
store receive times when the packets were received, wherein the receive times are based on the clock;
calculate, based on differences between the transmit times and the receive times, relative drift as a function of time between the clock and the second clock;
adjust, based on the relative drift, the clock circuit to eliminate the relative drift;
store adjustments to the clock circuit from the adjust operation; and
when the interface circuit or a second interface circuit in the second electronic device is reset, adapt the clock circuit based on the stored adjustments to reduce the relative drift while the interface circuit restores frequency lock with the second clock based on additional packets with additional transmit times that are received from the one or more antennas.
12 Assignments
0 Petitions
Accused Products
Abstract
An electronic device that reduces relative drift is described. In particular, an interface circuit in the electronic device may calculate, based on differences between transmit times when packets were transmitted by a second electronic device and receive times of the packets, relative drift as a function of time between a clock in the interface circuit and a second clock in the second electronic device. Then, the interface circuit may adjust, based on the relative drift, a clock circuit that provides the clock to eliminate the relative drift, and may store the adjustments to the clock circuit. Furthermore, when a wireless reset occurs, the interface circuit may adapt the clock circuit based on the stored adjustments to reduce the relative drift while the interface circuit restores frequency lock with the second clock based on additional packets with additional transmit times that are received from the second electronic device.
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Citations
20 Claims
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1. An electronic device, comprising:
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one or more antennas; a clock circuit that is configured to provide a clock; and an interface circuit communicatively coupled to the one or more antennas and the clock circuit, wherein the interface circuit is configured to; receive, from the one or more antennas, packets associated with a second electronic device, wherein a given packet comprises a transmit time, based on a second clock in the second electronic device, when the second electronic device transmitted the given packet; store receive times when the packets were received, wherein the receive times are based on the clock; calculate, based on differences between the transmit times and the receive times, relative drift as a function of time between the clock and the second clock; adjust, based on the relative drift, the clock circuit to eliminate the relative drift; store adjustments to the clock circuit from the adjust operation; and when the interface circuit or a second interface circuit in the second electronic device is reset, adapt the clock circuit based on the stored adjustments to reduce the relative drift while the interface circuit restores frequency lock with the second clock based on additional packets with additional transmit times that are received from the one or more antennas. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for reducing relative drift, comprising:
by an interface circuit of an electronic device; receiving, from one or more antennas in the electronic device, packets associated with a second electronic device, wherein a given packet comprises a transmit time, based on a second clock in the second electronic device, when the second electronic device transmitted the given packet; storing receive times when the packets were received, wherein the receive times are based on a clock in the electronic device; calculating, based on differences between the transmit times and the receive times, the relative drift as a function of time between the clock and the second clock; adjusting, based on the relative drift, a clock circuit in the electronic device that provides the clock to eliminate the relative drift; storing adjustments to the clock circuit from the adjusting operation; and when the interface circuit or a second interface circuit in the second electronic device is reset, adapting the clock circuit based on the stored adjustments to reduce the relative drift while the interface circuit restores frequency lock with the second clock based on additional packets with additional transmit times that are received from the one or more antennas.
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10. An electronic device, comprising:
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one or more antennas; a clock circuit that is configured to provide a clock; and an interface circuit communicatively coupled to the one or more antennas, wherein the interface circuit is configured to; receive, from the one or more antennas, packets associated with a second electronic device, wherein a given packet comprises a transmit time, based on a second clock in the second electronic device, when the second electronic device transmitted the given packet; store receive times when the packets were received, wherein the receive times are based on the clock; calculate, based on differences between the transmit times and the receive times, relative drift as a function of time between the clock and the second clock; adjust, based on the relative drift, the clock circuit to eliminate the relative drift; store adjustments to the clock circuit from the adjust operation; and adapt the clock circuit based on the stored adjustments to reduce the relative drift during a reset, the adapting being performed on a longer time scale than the adjusting. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method for reducing relative drift, comprising:
by an interface circuit of an electronic device; receiving, from one or more antennas in the electronic device, packets associated with a second electronic device, wherein a given packet comprises a transmit time, based on a second clock in the second electronic device, when the second electronic device transmitted the given packet; storing receive times when the packets were received, wherein the receive times are based on a clock in the electronic device; calculating, based on differences between the transmit times and the receive times, the relative drift as a function of time between the clock and the second clock; adjusting, based on the relative drift, a clock circuit in the electronic device that provides the clock to eliminate the relative drift; storing adjustments to the clock circuit from the adjusting operation; and adapting the clock circuit based on the stored adjustments to reduce the relative drift during a reset, the adapting being performed on a longer time scale than the adjusting.
Specification