Claims
- 1. An apparatus for discriminating and suppressing noise within an incoming signal, the apparatus comprising:
- a first signal processing means for processing said incoming signal to generate a first iteration signal, said first iteration signal being representative of a first predetermined parameter of said incoming signal;
- a second signal processing means for processing said first iteration signal to generate a second iteration signal, said second iteration signal being representative of a second predetermined parameter of said first iteration signal;
- a prediction means for generating a predicted value for said second iteration signal based on a plurality of earlier samples of said second iteration signal;
- a logic means for determining a difference between said second iteration signal and said predicted value, said logic means generating a logic output, said logic output having a first value when said difference exceeds a predetermined threshold value, said logic output having a second value when said difference does not exceed said predetermined threshold value; and
- a muting means for muting signals; said muting means being operatively connected to receive said incoming signal and said logic output, said muting means responding to said logic output to mute said incoming signal when said logic output is at one of said first value and said second value, said muting means responding to said logic output to not mute said incoming signal when said logic output is at the other of said first value and said second value.
- 2. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 1 wherein said first iteration signal represents average signal energy of said incoming signal.
- 3. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 1 wherein said second iteration signal comprises said first iteration signal normalized with respect to a predetermined value.
- 4. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 3 wherein said predetermined value is a maximum value expected for said first iteration signal.
- 5. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 4 wherein said second iteration signal represents a logarithmic expression.
- 6. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 2 wherein said second iteration signal comprises said first iteration signal normalized with respect to a predetermined value.
- 7. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 6 wherein said predetermined value is a maximum value expected for said first iteration signal.
- 8. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 7 wherein said second iteration signal represents a logarithmic expression.
- 9. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 2 wherein said first signal processing means effects an averaging algorithm in the form: ##EQU10## where .epsilon..sub.t =average signal energy,
- s.sub.i =i.sup.th sample of said incoming signal, and
- n=number of samples.
- 10. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 3 wherein said second signal processing means effects a normalizing algorithm in the form: ##EQU11## where P.sub.t =average signal energy normalized with respect to maximum signal energy,
- .epsilon..sub.t =average signal energy, and
- .epsilon..sub.max =maximum signal energy.
- 11. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 1 wherein said prediction means comprises a digital filter, said digital filter having at least as many taps as said plurality of earlier samples.
- 12. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 9 wherein said second signal processing means effects a normalizing algorithm in the form: ##EQU12## where P.sub.t =average signal energy normalized with respect to maximum signal energy,
- .epsilon..sub.t =average signal energy, and
- .epsilon..sub.max =maximum signal energy.
- 13. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 9 wherein said prediction means comprises a digital filter, said digital filter having at least as many taps as said plurality of earlier samples.
- 14. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 10 wherein said prediction means comprises a digital filter, said digital filter having at least as many taps as said plurality of earlier samples.
- 15. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 12 wherein said prediction means comprises a digital filter, said digital filter having at least as many taps as said plurality of earlier samples.
- 16. A method for discriminating and suppressing noise within an incoming signal, the method comprising the steps of:
- (a) generating a first iteration signal, said first iteration signal being representative of average signal energy of said incoming signal;
- (b) generating a second iteration signal, said second iteration signal being representative of said first iteration signal normalized with respect to a maximum signal energy expected for said incoming signal;
- (c) generating a predicted value for said second iteration signal based on a plurality of earlier samples of said second iteration signal;
- (d) determining a difference between said second iteration signal and said predicted value;
- (e) generating a control signal, said control signal having a first value when said difference exceeds a predetermined threshold value, said control signal having a second value when said difference does not exceed said predetermined threshold value; and
- (f) providing a muting means for muting signals; said muting means being operatively connected to receive said incoming signal and said control signal, said muting means responding to said control signal to mute said incoming signal when said control signal is at one of said first value and said second value, said muting means responding to said control signal to not mute said incoming signal when said control signal is at the other of said first value and said second value.
- 17. A method for discriminating and suppressing noise within an incoming signal as recited in claim 16 wherein said first iteration signal is generated according to the relationship: ##EQU13## where .epsilon..sub.t =average signal energy,
- s.sub.i =i.sup.th sample of said incoming signal, and
- n=number of samples.
- 18. A method for discriminating and suppressing noise within an incoming signal as recited in claim 16 wherein said second iteration signal is generated according to the relationship: ##EQU14## where P.sub.t =average signal energy normalized with respect to maximum signal energy,
- .epsilon..sub.t =average signal energy, and
- .epsilon..sub.max =maximum signal energy.
- 19. A method for discriminating and suppressing noise within an incoming signal as recited in claim 16 wherein said predicted value is generated according to the relationship: ##EQU15## where P.sub.pred =predicted average signal energy normalized to maximum expected signal energy of said incoming signal,
- .beta..sub.i =a scaling factor,
- P.sub.i =i.sup.th sample of normalized average signal energy, and
- n=number of samples.
- 20. A method for discriminating and suppressing noise within an incoming signal as recited in claim 17 wherein said second iteration signal is generated according to the relationship: ##EQU16## where P.sub.t =average signal energy normalized with respect to maximum signal energy,
- .epsilon..sub.t =average signal energy, and
- .epsilon..sub.max =maximum signal energy.
- 21. A method for discriminating and suppressing noise within an incoming signal as recited in claim 17 wherein said predicted value is generated according to the relationship: ##EQU17## where P.sub.pred =predicted average signal energy normalized to maximum expected signal energy of said incoming signal,
- .beta..sub.i =a scaling factor, and
- P.sub.i =i.sup.th sample of normalized average signal energy.
- 22. A method for discriminating and suppressing noise within an incoming signal as recited in claim 18 wherein said predicted value is generated according to the relationship: ##EQU18## where P.sub.pred =predicted average signal energy normalized to maximum expected signal energy of said incoming signal,
- .beta..sub.i =a scaling factor, and
- P.sub.i =i.sup.th sample of normalized average signal energy.
- 23. An apparatus for discriminating and suppressing noise within an incoming signal, the apparatus comprising:
- a first signal processing means for processing said incoming signal to generate a first iteration signal, said first iteration signal representing average signal energy of said incoming signal, said first signal processing means effecting an averaging algorithm in the form: ##EQU19## where .epsilon..sub.t =average signal energy,
- s.sub.i =i.sup.th sample of said incoming signal, and
- n=number of samples;
- a second signal processing means for processing said first iteration signal to generate a second iteration signal, said second iteration signal being representative of a predetermined parameter of said first iteration signal;
- a prediction means for generating a predicted value for said second iteration signal based on a plurality of earlier samples of said second iteration signal;
- a logic means for determining a difference between said second iteration signal and said predicted value, said logic means generating a logic output, said logic output having a first value when said difference exceeds a predetermined threshold value, said logic output having a second value when said difference does not exceed said predetermined threshold value; and
- a muting means for muting signals; said muting means being operatively connected to receive said incoming signal and said logic output, said muting means responding to said logic output to mute said incoming signal when said logic output is at one of said first value and said second value, said muting means responding to said logic output to not mute said incoming signal when said logic output is at the other of said first value and said second value.
- 24. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 23 wherein said second iteration signal comprises said first iteration signal normalized with respect to the maximum value expected for said first iteration signal, said second signal processing means effecting a normalizing algorithm in the form: ##EQU20## where P.sub.t =average signal energy normalized with respect to maximum signal energy,
- .epsilon..sub.t =average signal energy, and
- .epsilon..sub.max =maximum signal energy.
- 25. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 23 wherein said predicted value is generated according to the relationship: ##EQU21## where P.sub.pred =predicted average signal energy normalized to maximum expected signal energy of said incoming signal,
- .beta..sub.i =a scaling factor, and
- P.sub.i =i.sup.th sample of normalized average signal energy.
- 26. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 24 wherein said predicted value is generated according to the relationship: ##EQU22## where P.sub.pred =predicted average signal energy normalized to maximum expected signal energy of said incoming signal,
- .beta..sub.i =a scaling factor, and
- P.sub.i =i.sup.th sample of normalized average signal energy.
- 27. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 23 wherein said prediction means comprises a digital filter, said digital filter having at least as many taps as said plurality of earlier samples.
- 28. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 24 wherein said prediction means comprises a digital filter, said digital filter having at least as many taps as said plurality of earlier samples.
- 29. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 25 wherein said prediction means comprises a digital filter, said digital filter having at least as many taps as said plurality of earlier samples.
- 30. An apparatus for discriminating and suppressing noise within an incoming signal as recited in claim 26 wherein said prediction means comprises a digital filter, said digital filter having at least as many taps as said plurality of earlier samples.
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 07/887,470 filed May 22, 1992 abandoned.
The following applications contain subject matter similar to the subject matter of this application:
U.S. application Ser. No. 07/887,076, filed May 22, 1992, Attorney Docket Number 204 928, entitled "Improved Apparatus and Method for Discriminating and Suppressing Noise within an Incoming Signal".
U.S. application Ser. No. 07/887,469, filed, May 22, 1992, Attorney Docket Number 204 978, entitled "Apparatus and Method for Attenuating a Received Signal in Response to Presence of Noise".
US Referenced Citations (7)
Continuations (1)
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Number |
Date |
Country |
Parent |
887470 |
May 1992 |
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