Impulse noise mitigation under out-of-band interference conditions
AssigneeMaxLinear, Inc.
InventorsAndy Lo, Sugbong Kang
Life of this patent
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Abstract
A noise abatement method and system for impulse noise in an RF receiver where the RF analog signal is converted to a digital signal prior to being connected to a demodulator. Two filters are used to detect impulse noise signals even under out-of-band interferer conditions, and prevent the impulse noise from reaching the input to the demodulator. A first of the two filters detects impulse noise using signals lower than the frequency bandwidth of the desired signal, and a second of the two filters detects impulse noise using signals higher the frequency bandwidth of the desired signal. A mean magnitude of the signal is detected over a predetermined time T and is used to select which filter to use for noise abatement.
Claims11
A method for impulse noise mitigation, comprising:
- a) forming an impulse noise mitigation circuit;
- b) forming two complex high pass filters within said impulse noise mitigation circuit;
- c) setting a cut-off frequencies of the two complex high pass filters to bound a frequency bandwidth of a desired signal, wherein a first of the two complex high pass filters allows frequencies higher than the frequency bandwidth of the desired signal, and wherein a second of the two complex filters allows frequencies lower than the frequency bandwidth of the desired signal;
- d) measuring a first signal response of the first filter;
- e) measuring a second signal response of the second filter;
- f) computing and storing a mean magnitude separately for the first signal response to the first filter and the second signal response of the second filter;
- g) selecting the first filter for impulse noise mitigation if the mean magnitude for the second filter is greater than the mean magnitude response of the first filter;
- and
- h) selecting the second filter for impulse noise mitigation if the mean magnitude for the first filter is greater than the second filter.
A system for impulse noise mitigation, comprising:
- a) an impulse noise mitigation circuit (INMC) connected to an output of an analog to digital converter (ADC) converting an analog RF signal to a digital signal;
- b) said INMC further comprising two complex high pass filters, which bound a bandwidth of a desired RF signal;
- c) a response of each filter measured over a predetermined time span and a mean magnitude value of the effect on the output of the ADC for each filter computed and compared;
- d) a first filter of said two complex high pass filters selected to abate impulse noise and other interferer when the mean magnitude value of a second filter of said two complex high pass filters is greater than the mean magnitude value of the first filter;
- and
- e) said second filter of said two complex high pass filters selected to abate impulse noise and other interferer when the mean magnitude value of the first filter is greater than the mean magnitude value of the second filter;
Dependencies are inferred from the claim text.