System and method for automatic recovery and covariance adjustment in linear filters
First Claim
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1. A communications device, comprising:
- a time/frequency error measurement circuit that receives a communications signal and measures its timing and frequency errors within the communications signal;
a Kalman filter that receives the communications signal from the time/frequency error measurement circuit and processes the communications signal using a multi-level state error covariance matrix P for controlling any Kalman gain in the Kalman filter; and
an online error monitoring circuit operative with the Kalman filter and configured to monitor any actual state errors in time and frequency and control the multi-level state error covariance matrix P based on a measured error threshold, wherein levels within the multi-level state error covariance P are defined initially as true initial errors.
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Abstract
A communications device includes a time/frequency error measurement circuit that receives a communications signal and measures its timing and frequency errors. A Kalman filter receives the communications signal from the time/frequency error measurement circuit and processes the signal using a multi-level state error covariance matrix P for controlling the Kalman gain in the Kalman filter. An on-line monitoring circuit is operative with the Kalman filter for monitoring the actual state errors in time and frequency and controlling the state error covariance matrix P based on a measured error threshold.
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Citations
19 Claims
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1. A communications device, comprising:
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a time/frequency error measurement circuit that receives a communications signal and measures its timing and frequency errors within the communications signal; a Kalman filter that receives the communications signal from the time/frequency error measurement circuit and processes the communications signal using a multi-level state error covariance matrix P for controlling any Kalman gain in the Kalman filter; and an online error monitoring circuit operative with the Kalman filter and configured to monitor any actual state errors in time and frequency and control the multi-level state error covariance matrix P based on a measured error threshold, wherein levels within the multi-level state error covariance P are defined initially as true initial errors. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A communications system, comprising:
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a plurality of signal sources that transmit communications signals operating at respectively different data rates over respective ones of a plurality of communications links; a receiver that receives the plurality of communications signals, and comprising a a front end demodulator having a receiver clock that is used in the recovery of data from communications signals received from the signal sources; a time/frequency error measurement circuit that receives the communications signal and measures any timing and frequency errors with the communications signals; a Kalman filter that receives communications signals from the time/frequency error measurement circuit and processes the communications signals using a multi-level state error covariance matrix P for controlling any Kalman gain within the Kalman filter; an online error monitoring circuit operative with the Kalman filter configured to monitor actual state errors in time and frequency and control state error covariance matrix P based on a measured error threshold; and a time/frequency tracker operative to acquire and track time and frequency variations in synchronization signals conveyed over the communications links and operative to synchronize the receiver clock with a clock signal embedded within the communications signal, wherein levels within the multi-level state error covariance P are defined initially as true initial errors. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A method of communicating, comprising:
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receiving a communications signal and measuring any timing and frequency errors within a time/frequency error measurement circuit; processing data from the time/frequency error measurement circuit using a multi-level state error covariance matrix P for controlling any Kalman gain in a Kalman filter; monitoring actual state errors in time and frequency and controlling the multi-level state error covariance matrix P based on a measured error threshold; and resetting the state error covariance matrix P from a theoretical P to an actual to open up bandwidth to an actual state error covariance matrix P when one of at least excessive time and frequency errors occur. - View Dependent Claims (18, 19)
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Specification