Fast recovery from incorrect carrier phase integer locking
First Claim
1. A method of determining a position of a device using a signal received from a reference emitter, the method comprising:
- receiving, with a receiver of the device, the signal from the reference emitter;
determining a state of a first filter of the receiver based on the signal, wherein the state of the first filter includes a first carrier phase ambiguity estimate comprising a floating value;
determining a state of a second filter of the receiver based on the signal, wherein the state of the second filter includes a second carrier phase ambiguity estimate comprising a fixed value;
determining whether the state of the second filter is consistent with at least one of the state of the first filter and a previous state of the second filter, wherein determining whether the state of the second filter is consistent with the state of the first filter comprises determining whether an estimate from the state of the second filter is consistent with a variance of an estimate from the state of the first filter, and wherein determining whether the state of the second filter is consistent with the previous state of the second filter comprises determining whether a measurement prediction residual based on a current measurement is consistent with a measurement prediction residual determined in the previous state of the second filter;
maintaining the state of the second filter in response to the device determining that the state of the second filter is consistent with the at least one of the state of the first filter and the previous state of the second filter;
changing the state of the second filter to the state of the first filter in response to the device determining that the state of the second filter is not consistent with the at least one of the state of the first filter and the previous state of the second filter; and
determining the position of the device based on the state of the second filter.
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Accused Products
Abstract
Determining a position of a device using a signal received from a reference emitter includes: receiving the signal; determining a state of a first filter, the state of the first filter including a first carrier phase ambiguity estimate that includes a floating value; determining a state of a second filter, the state of the second filter including a second carrier phase ambiguity estimate that includes a fixed value; determining whether the state of the second filter is consistent with one other filter state or measurement; maintaining the state of the second filter in response to the device determining that the state of the second filter is consistent with the other filter state; changing the state of the second filter to the state of the first filter in response to the device determining that the state of the second filter is not consistent with the other filter state.
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Citations
14 Claims
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1. A method of determining a position of a device using a signal received from a reference emitter, the method comprising:
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receiving, with a receiver of the device, the signal from the reference emitter; determining a state of a first filter of the receiver based on the signal, wherein the state of the first filter includes a first carrier phase ambiguity estimate comprising a floating value; determining a state of a second filter of the receiver based on the signal, wherein the state of the second filter includes a second carrier phase ambiguity estimate comprising a fixed value; determining whether the state of the second filter is consistent with at least one of the state of the first filter and a previous state of the second filter, wherein determining whether the state of the second filter is consistent with the state of the first filter comprises determining whether an estimate from the state of the second filter is consistent with a variance of an estimate from the state of the first filter, and wherein determining whether the state of the second filter is consistent with the previous state of the second filter comprises determining whether a measurement prediction residual based on a current measurement is consistent with a measurement prediction residual determined in the previous state of the second filter; maintaining the state of the second filter in response to the device determining that the state of the second filter is consistent with the at least one of the state of the first filter and the previous state of the second filter; changing the state of the second filter to the state of the first filter in response to the device determining that the state of the second filter is not consistent with the at least one of the state of the first filter and the previous state of the second filter; and determining the position of the device based on the state of the second filter. - View Dependent Claims (2, 3, 4)
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5. A device for determining a position of the device using a signal received from a reference emitter, the device comprising:
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a wireless receiver for wirelessly receiving the signal from the reference emitter; and a processor, communicatively coupled to the wireless receiver, configured to; determine a state of a first filter based on the signal, wherein the state of the first filter includes a first carrier phase ambiguity estimate comprising a floating value; determine a state of a second filter based on the signal, wherein the state of the second filter includes a second carrier phase ambiguity estimate comprising a fixed value; determine whether the state of the second filter is consistent with at least one of the state of the first filter and a previous state of the second filter, wherein determining whether the state of the second filter is consistent with the state of the first filter comprises determining whether an estimate from the state of the second filter is consistent with a variance of an estimate from the state of the first filter, and wherein determining whether the state of the second filter is consistent with the previous state of the second filter comprises determining whether a measurement prediction residual based on a current measurement is consistent with a measurement prediction residual determined in the previous state of the second filter; maintain the state of the second filter in response to the processor determining that the state of the second filter is consistent with the at least one of the state of the first filter and the previous state of the second filter; change the state of the second filter to the state of the first filter in response to the processor determining that the state of the second filter is not consistent with the at least one of the state of the first filter and the previous state of the second filter; and determine the position of the device based on the state of the second filter. - View Dependent Claims (6, 7)
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8. A device for determining a position of the device using a signal received from a reference emitter, the device comprising:
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receiving means for wirelessly receiving the signal from the reference emitter; first filtering means for determining a first state based on the signal, wherein the first state includes a first carrier phase ambiguity estimate comprising a floating value; second filtering means for determining a second state based on the signal, wherein the second state includes a second carrier phase ambiguity estimate comprising a fixed value; determining means for determining whether the second state is consistent with at least one of the first state of the first filtering means and a previous state of the second filtering means, wherein the determining means comprises means for wherein determining whether the second state of the second filtering means is consistent with the first state of the first filtering means comprises determining whether an estimate from the state of the second filter is consistent with a variance of an estimate from the state of the first filter, and wherein the determining means comprises means for determining whether a measurement prediction residual based on a current measurement is consistent with a measurement prediction residual determined in the previous state of the second filtering means; maintaining means for maintaining the second state in response to the device determining that the second state is consistent with the at least one of the first state of the first filtering means and the previous state of the second filtering means; changing means for changing the second state to the first state in response to the device determining that the second state is not consistent with the at least one of the first state of the first filtering means and the previous state of the second filtering means; and positioning means for determining the position of the device based on the second state. - View Dependent Claims (9, 10)
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11. A non-transitory processor-readable storage medium comprising processor-readable instructions configured to cause a processor of a device to:
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receive a signal from a reference emitter; determine a state of a first filter based on the signal, wherein the state of the first filter includes a first carrier phase ambiguity estimate comprising a floating value; determine a state of a second filter based on the signal, wherein the state of the second filter includes a second carrier phase ambiguity estimate comprising a fixed value; determine whether the state of the second filter is consistent with at least one of the state of the first filter and a previous state of the second filter, wherein the instructions configured to cause the processor to determine whether the state of the second filter is consistent with the state of the first filter comprise instructions configured to cause the processor to determine whether an estimate from the state of the second filter is consistent with a variance of an estimate from the state of the first filter, and wherein the instructions configured to cause the processor to determine whether the state of the second filter is consistent with the previous state of the second filter comprise instructions configured to cause the processor to determine whether a measurement prediction residual based on a current measurement is consistent with a measurement prediction residual determined in the previous state of the second filter; maintain the state of the second filter in response to the device determining that the state of the second filter is consistent with the at least one; change the state of the second filter to the state of the first filter in response to the device determining that the state of the second filter is not consistent with the at least one or the measurement; and determine a position of the device based on the state of the second filter. - View Dependent Claims (12, 13, 14)
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Specification