State estimation for time synchronization
AssigneeCommScope Technologies LLC
InventorStuart D. Sandberg
Life of this patent
Estimating the term…
Abstract
In one embodiment, a local clock is synchronized to a master clock using a Kalman filter to determine state variables using a state transition matrix that includes at least one coefficient that is associated with a digital-to-analog converter (DAC), where the state variables include a unit step variable indicative of a unit step for the system. The local clock is controlled based on the state variables determined using the Kalman filter. The unit step is indicative of an amount by which the frequency of the local clock signal changes in response to a change in the digital input of the DAC.
Claims23
A system comprising:
- a local clock configured to output a local clock signal as a function of an analog control input, the local clock signal having a frequency;
- and
- a digital-to-analog converter (DAC) configured to output an analog output signal as a function of a digital input, wherein the analog control input used by the local clock is a function of the analog output signal output by the DAC;
- wherein the system has a unit step that is indicative of an amount by which the frequency of the local clock signal changes in response to a change in the digital input of the DAC;
- wherein the system is configured to synchronize the local clock to a master clock using a Kalman filter to determine state variables using a state transition matrix that includes at least one coefficient that is associated with the DAC, wherein the state variables include a unit step variable indicative of the unit step;
- and
- wherein the system is used to control the local clock based on the state variables determined using the Kalman filter.
A method of synchronizing a local lock to a master clock, the method comprising:
- outputting, by the local clock, a local clock signal as a function of an analog control input, the local clock signal having a frequency;
- outputting, by a digital-to-analog converter (DAC), an analog output signal as a function of a digital input, wherein the analog control input used by the local clock is a function of the analog output signal output by the DAC, wherein a unit step is indicative of an amount by which the frequency of the local clock signal changes in response to a change in the digital input of the DAC;
- and
- using a Kalman filter to determine state variables using a state transition matrix that includes at least one coefficient that is associated with the DAC, wherein the state variables include a unit step variable indicative of the unit step;
- and
- controlling the local clock based on the state variables determined using the Kalman filter.
Dependencies are inferred from the claim text.