Noise ingress cancelation
AssigneeCisco Technology, Inc.
InventorsLEO MONTREUIL, RICK MELLER
Life of this patent
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Abstract
A demodulator can include an ingress exciser configured to remove ingress noise from a burst mode digital input signal that is above a predetermined threshold and resides within a narrowband. An adaptive equalizer can be configured to adaptively equalize an estimate of the signal provided from the ingress exciser and to provide an adaptively equalized signal. An ingress predictor can be configured to subtract an estimate of remaining predicted ingress noise from the adaptively equalized signal to provide a resultant signal that is substantially free of the ingress noise.
Claims20
An apparatus comprising:
- an ingress exciser configured to remove ingress noise from a burst mode digital input signal that is above a predetermined threshold and resides within a narrowband;
- an adaptive equalizer configured to adaptively equalize an estimate of the signal provided from the ingress exciser and to provide an adaptively equalized signal;
- and
- an ingress predictor configured to subtract an estimate of remaining predicted ingress noise from the adaptively equalized signal to provide a resultant signal that is substantially free of the ingress noise.
A method, comprising:
- receiving a reverse path burst mode signal from at least one modem;
- excising ingress noise from within a predetermined notch of the received burst mode signal to provide an excised signal;
- gain scaling and adaptively linearly equalizing an estimation of the excised signal to provide an adaptively equalized signal;
- predicting ingress noise remaining in the adaptively equalized signal for a valid burst condition based on a hard decision output that is substantially free of ingress;
- and
- subtracting the predicted ingress noise from the adaptively equalized signal to provide an output that is substantially free of the predicted ingress noise.
A system comprising:
- reverse path electronics comprising:
- a demodulator configured to receive a reverse-path burst-mode communication signal from at least one downstream modem, the demodulator comprising:
- an ingress exciser configured to remove ingress noise from a digital representation of the reverse-path burst-mode communication signal for frequencies of the ingress noise having power above a predetermined threshold and residing within a narrowband of the reverse-path burst-mode communication signal;
- an adaptive equalizer configured to adaptively equalize an estimate of the signal provided by the ingress exciser and to provide an adaptively equalized signal;
- and
- an ingress predictor configured to subtract an estimate of predicted ingress noise from the adaptively equalized signal to provide a resultant signal that is substantially free of the ingress noise, the demodulator providing an output signal based on the resultant signal;
- forward path electronics configured to communicate forward-path signals to the at least one downstream modem to provide data addressed to the at least one downstream modem.
Dependencies are inferred from the claim text.