Communication system noise cancellation power signal calculation techniques
AssigneeTellabs Operations, Inc.
InventorsRavi Chandran, Bruce E. Dunne, Daniel J. Marchok
Life of this patent
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Abstract
In order to enhance the quality of a communication signal derived from speech and noise, a filter divides the communication signal into a plurality of frequency band signals. A calculator generates a plurality of power band signals each having a power band value and corresponding to one of the frequency band signals. The power band values are based on estimating, over a time period, the power of one of the frequency band signals. The time period is different for different ones of the frequency band signals. The power band values are used to calculate weighting factors which are used to alter the frequency band signals that are combined to generate an improved communication signal.
Claims30
In a communication system for processing a communication signal derived from speech and noise, apparatus for enhancing the quality of the communication signal comprising
- a frequency band divider arranged to divide the communication signal into a plurality of frequency band signals;
- and
- a calculator generating a plurality of power band signals having power band values and corresponding to the frequency band signals, the power band values being based on estimating over time periods the power of the frequency band signals, the time periods being different for at least two of the frequency band signals, calculating weighting factors based at least in part on the power band values, altering the frequency band signals in response to the weighting factors to generate weighted frequency band signals and generating a communication signal with enhanced quality in response to the weighted frequency band signals.
In a communication system for processing a communication signal derived from speech and noise, a method of enhancing the quality of the communication signal comprising:
- dividing the communication signal into a plurality of frequency band signals;
- generating a plurality of power band signals having power band values and corresponding to the frequency band signals, the power band values being based on estimating over time periods the power of one of the frequency band signals, the time periods being different for at least two of the frequency band signals;
- calculating weighting factors based at least in part on the power band values;
- altering the frequency band signals in response to the weighting factors to generate weighted frequency band signals;
- and
- generating a communication signal with enhanced quality in response to the weighted frequency band signals.
In a communication system for processing a communication signal derived from speech and noise, apparatus for enhancing the quality of the communication signal comprising:
- a frequency band divider arranged to divide the communication signal into a plurality of frequency band signals;
- and
- a calculator generating a plurality of power band signals having power band values and corresponding to the frequency band signals, generating a dropout signal in the event that at least one characteristic of the communication signal has a defined attribute, changing the rate at which the power band values are allowed to change during the presence of the dropout signal, calculating weighting factors based at least in part on the power band values, altering the frequency band signals in response to the weighting factors to generate weighted frequency band signals and generating a communication signal with enhanced quality in response to the weighted frequency band signals.
In a communication system for processing a communication signal derived from speech and noise, a method of enhancing the quality of the communication signal comprising:
- dividing the communication signal into a plurality of frequency band signals;
- generating a plurality of power band signals having power band values and corresponding to the frequency band signals;
- generating a dropout signal in the event that at least one characteristic of the communication signal has a defined attribute;
- changing the rate at which the power band values are allowed to change during the presence of the dropout signal;
- calculating weighting factors based at least in part on the power band values;
- altering the frequency band signals in response to the weighting factors to generate weighted frequency band signals;
- and
- generating a communication signal with enhanced quality in response to the weighted frequency band signals.
In a communication system for processing a communication signal derived from speech and noise, apparatus for enhancing the quality of the communication signal comprising:
- a frequency band divider arranged to divide the communication signal into a plurality of frequency band signals;
- and
- a calculator generating a plurality of power band signals having power band values and corresponding to the frequency band signals, generating a new environment signal in the event that the communication signal is detected at the beginning of a call or in response to at least one characteristic of the communication signal having a defined attribute, changing the rate at which the power band values are allowed to change during the presence of the new environment signal, calculating weighting factors based at least in part on the power band values, altering the frequency band signals in response to the weighting factors to generate weighted frequency band signals and generating a communication signal with enhanced quality in response to the weighted frequency band signals.
In a communication system for processing a communication signal derived from speech and noise, a method of enhancing the quality of the communication signal comprising:
- dividing the communication signal into a plurality of frequency band signals;
- generating a plurality of power band signals having power band values and corresponding to the frequency band signals;
- generating a new environment signal in the event that the communication signal is detected at the beginning of a call or in response to at least one characteristic of the communication signal having a defined attribute;
- changing the rate at which the power band values are allowed to change during the presence of the new environment signal;
- calculating weighting factors based at least in part on the power band values;
- altering the frequency band signals in response to the weighting factors to generate weighted frequency band signals;
- and
- generating a communication signal with enhanced quality in response to the weighted frequency band signals.
Dependencies are inferred from the claim text.