Back to results
US 6,487,295 B1Granted
Adaptive filtering system and method
AssigneeOrtivus AB
InventorsNils Lofgren, Per Karlsson, Gunilla Lundahl, Fredrik Lundqvist
Life of this patent
Estimating the term…
Abstract
A signal filter includes a first adaptive filter receiving a desired signal containing a noise component and a first noise correlated reference signal, and outputting a first filtered output signal. A second adaptive filter, receives the desired signal containing the noise component and a second noise correlated reference signal and outputs a second filtered output signal. Signal filter parameters of the second adaptive filter are controlled based on the first filtered output signal and the second filtered output signal.
Claims18
A signal filter comprising:
- a first adaptive filter receiving a desired signal containing a noise component and a first noise correlated reference signal, and outputting a first filtered output signal;
- and
- a second adaptive filter, receiving the desired signal containing the noise component and a second noise correlated reference signal and outputting a second filtered output signal, wherein signal filter parameters of the second adaptive filter are controlled based on the first filtered output signal and the second filtered output signal.
A signal filtering method comprising:
- receiving a desired signal containing a noise component;
- receiving a noise correlated reference signal;
- filtering the noise correlated reference signal using a first set of adaptive parameters to provide a first filtered noise correlated reference signal;
- subtracting the first filtered noise correlated reference signal from the desired signal containing the noise component to provide a first output signal;
- controlling the first set of adaptive parameters based on the first output signal;
- filtering the noise correlated reference signal using a second set of adaptive parameters and a signal corresponding to the first output signal to provide a second filtered noise correlated reference signal;
- subtracting the second filtered noise correlated reference signal from the desired signal containing the noise component to provide a second output signal, the second output signal being the desired signal with a minimized noise component;
- and
- controlling the second set of adaptive parameters based on the second output signal.
6 more elements
A signal filtering system comprising:
- a coarse filter comprising,
- a subtractor for subtracting a first filtered noise correlated reference signal from a desired signal containing a noise component and providing a first output signal,
- a filter for receiving and filtering a noise correlated reference signal using a first set of adaptive parameters and outputting the first filtered noise correlated reference signal, and
- an adaptive processor for adaptively processing the adaptive parameters based on the first output signal;
- and
- a signal filter comprising,
- a subtractor for subtracting a second filtered noise correlated reference signal from the desired signal containing the noise component and providing a second output signal,
- a filter for receiving and filtering the noise correlated reference signal using a second set of adaptive parameters and information corresponding to the first output signal and outputting the second filtered noise correlated reference signal, and
- an adaptive processor for adaptively processing the second adaptive parameters based on the second output signal.
6 more elements
A signal filter comprising:
- a first filter receiving a noise correlated reference signal and outputting a filtered noise correlated reference signal based on a set of parameters and a weighted signal;
- a subtractor for subtracting the filtered noise correlated reference signal from a desired signal including a noise component and outputting a first output signal;
- a processor for modifying the set of parameters based on the first output signal;
- a second filter receiving the noise correlated reference signal and outputting a second filtered noise correlated reference signal based on a second set of parameters;
- a second subtractor for subtracting the second filtered noise correlated reference signal from the desired signal including a noise component and outputting an second output signal;
- and
- a second processor for modifying the second set of parameters based on the first output signal and the second output signal.
4 more elements
Dependencies are inferred from the claim text.