Low complexity tone/voice discrimination method using a rising edge of a frequency power envelope

Patent metadata

Field	Value
Publication number	US-9479846-B2
Application number	US-201514841611-A
Country	US
Kind code	B2
Filing date	Aug 31, 2015
Priority date	Dec 9, 2013
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

An apparatus comprising a decision circuit, a detector circuit and a processing circuit. The decision circuit may be configured to generate a confirmation signal in response to a first lock signal and a second lock signal. The detector circuit may be configured to generate the first lock signal in response to a filtered version of an input signal being above a threshold. The processing circuit may be configured to generate the second lock signal in response to a power signal received from the detector circuit. The processing circuit generates the second lock signal by analyzing the rising edge of a frequency power envelope of the power signal.

First claim

We claim:

1. A tone detection apparatus, comprising one or more integrated circuit to:
receive an input signal and generate a power signal indicative of the input signal;
generate a lock signal indicative of a rising edge of a frequency power envelope of the power signal; and
generate a tone confirmation signal based on at least the lock signal.

2. The apparatus of claim 1 , wherein the one or more integrated circuit comprises:
a detector circuit to receive the input signal and generate the power signal;
a processing circuit to receive the power signal and generate the lock signal, wherein the processing circuit is to generate the lock signal in response to a change in the power signal exceeding a predetermined power change threshold; and
a decision circuit to generate the tone confirmation signal based at least on the lock signal.

3. The apparatus of claim 2 , wherein the processing circuit is to:
determine a change in the power signal between two consecutive signal sampling time windows; and
output the lock signal in response to the change exceeding the predetermined power change threshold.

4. The apparatus of claim 3 , wherein the processing circuit is to:
determine a change in the power signal between three or more consecutive signal sampling time windows; and
output the lock signal in response to the changes exceeding one or more predetermined threshold.

5. The apparatus of claim 3 , wherein the processing circuit is to:
compute a difference between a current power signal associated with a current sampling time window and a prior power signal associated with a previous sampling time window.

6. The apparatus of claim 5 , wherein the processing circuit is to determine the current power signal is greater than the prior power signal if the power change exceeds 9 dB.

7. The apparatus of claim 1 , wherein:
the one or more integrated circuit further comprises a narrow band pass tone frequency filter to generate a filtered version of the input signal; and
the one or more integrated circuit is to generate the power signal based on the filtered version of the input signal.

8. The apparatus of claim 1 , wherein the one or more integrated circuit is further to:
generate an additional lock signal in response to a filtered version of the input signal being above a predetermined power threshold; and
generate the tone confirmation signal based on both the lock signal and the additional lock signal.

9. The apparatus of claim 8 , wherein the one or more integrated circuit further comprises:
a detector circuit including:
a narrow band pass tone frequency filter to generate the filtered version of the input signal;
a tone frequency power circuit to compute the power signal based on the filtered version of the input signal;
a low pass filter to determine an average of the power signal; and
a comparator to compare the average power signal with the power threshold, and output the additional lock signal in response to the average filtered input signal exceeding the power threshold.

10. A method for detecting a tone, the method comprising:
receiving an input signal and generate a power signal indicative of the input signal;
generating a lock signal indicative of a rising edge of a frequency power envelope of the power signal; and
generating a tone confirmation signal based on at least the lock signal.

11. The method of claim 10 , wherein the method further comprises generating the lock signal in response to a frequency change in the power signal exceeding a predetermined power signal change threshold.

12. The method of claim 11 , further comprising:
determining a change in the power signal between two consecutive signal sampling time windows; and
outputting the lock signal in response to the change exceeding a predetermined threshold.

13. The method of claim 12 , further comprising:
determining a change in the power signal between three or more consecutive signal sampling time windows; and
outputting the lock signal in response to the changes exceeding one or more predetermined threshold.

14. The method of claim 12 , further comprising:
computing a difference between a current power signal associated with a current sampling time window and a prior power signal associated with a previous sampling time window.

15. The method of claim 11 , outputting the lock signal in response to the current power signal being greater than the prior power signal by at least 9 dB.

16. The method of claim 10 , further comprising:
band pass filtering the input signal; and
generating the power signal based on the band-pass filtered version of the input signal.

17. The method of claim 10 , further comprising:
generating an additional lock signal in response to a filtered version of the input signal being above a predetermined power threshold; and
generating the tone confirmation signal based on both the lock signal and the additional lock signal.

18. The method of claim 17 ,
band-pass filtering the input signal;
computing the power signal based on the band-pass filtered version of the input signal;
low pass filtering the power signal to determine an average power signal;
comparing the average power signal with the power threshold; and
outputting the additional lock signal in response to the average power signal exceeding the power threshold.

19. A tone detection apparatus, comprising one or more integrated circuit to:
receive an input signal and generate a power signal indicative of the input signal;
generate a lock signal indicative of a rising edge of a frequency power envelope of the power signal;
generate an additional lock signal in response to a filtered version of the input signal being above a predetermined power threshold; and
generate the tone confirmation signal based on both the lock signal and the additional lock signal.

20. The apparatus of claim 19 , wherein the one or more integrated circuit further comprises:
a detector circuit including:
a narrow band pass tone frequency filter to generate the filtered version of the input signal;
a tone frequency power circuit to compute the power signal based on the filtered version of the input signal;
a low pass filter to determine an average of the power signal;
a comparator to compare the average power signal with the power threshold, and
output the additional lock signal in response to the average filtered input signal exceeding the power threshold

a processing circuit to:
receive the power signal;
determine a change in the power signal between two consecutive signal sampling time windows; and
output the lock signal in response to the change exceeding the predetermined power change threshold; and

a decision circuit to generate the tone confirmation signal based on both the lock signal and the additional lock signal.

Assignees

• Intel Corp

Inventors

• Dzik Dariusz
• Barazesh Bahman

Classifications

• H04M1/24

  Arrangements for testing · CPC title

• H04M11/06

  Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors · CPC title

• H04M2203/2027

  Live party detection · CPC title

• H04Q1/457 Primary

  with conversion of multifrequency signals into digital signals · CPC title

• H04Q1/46 Primary

  comprising means for distinguishing between a signalling current of predetermined frequency and a complex current containing that frequency, e.g. speech current · CPC title