Method and device for estimating a pattern in a signal

• US 9,208,799 B2
• Filed: 11/07/2011
• Issued: 12/08/2015
• Est. Priority Date: 11/10/2010
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Gigi, Ercan Ferit
• Primary Examiner(s): Shah, Paras D
• Assistant Examiner(s): Sirjani, Fariba
• Application Number:
  US13/883,647
• Publication Number:
  US 20130231926A1
• Time in Patent Office: 1,492 Days
• US Class Current: 1/1
• CPC Class Codes: G10L 25/90 Pitch determination of speech signals

Abstract

The present invention relates to a method for estimating a pattern, in particular a pitch and/or a fundamental frequency, in a signal having a periodic, quasiperiodic or virtually periodic component, wherein the signal is transformed from a time-domain to a frequency-domain to obtain a spectrum of the signal, the spectrum is processed to obtain a zero-phase spectrum of the signal, the spectrum of the signal is transformed to the time-domain to obtain a correlation signal, the spectrum and the correlation signals are combined to a combined spectrum, and the pattern is estimated on the basis of the combined spectrum.

Claims

1. A method for estimating a fundamental frequency pattern in a signal having a periodic, quasi-periodic or virtually periodic component, operable in a processing system, the method comprising:

transforming, by the processing system, the signal from a time-domain to a frequency-domain to obtain a spectrum of the signal,

processing, by the processing system, the spectrum to obtain a zero-phase spectrum of the signal,

transforming, by the processing system, a positive portion of the zero-phase spectrum of the signal to the time-domain to obtain a correlation signal,

multiplying, by the processing system, the spectrum and the correlation signal to a combined spectrum, and

estimating, by the processing system, the fundamental frequency pattern of the signal based on the combined spectrum.

2. A device for estimating a pitch pattern in a signal having a periodic, quasi-periodic or virtually periodic component, the device comprising:

a processing unit in communication with a memory, the memory include code which when assessed by the processing unit causes the processing unit to;

transform the signal from a time-domain to a frequency-domain to obtain a spectrum of the signal by performing a Fourier Transform of the signal,

process the spectrum to obtain a zero-phase spectrum of the signal by a DC notch filter

transform a positive portion of the spectrum of the signal to the time-domain to obtain a correlation signal by performing an Inverse Fourier Transform,

combine the spectrum and the correlation signal to obtain a combined spectrum by multiplying the spectrum and the correlation signal and

estimate the pitch pattern of the signal based on the combined spectrum.

4. The device of claim 2, wherein transforming the signal, by the processing system comprises performing a Fourier Transformation on the signal.

5. The device of claim 2, wherein the signal is processed by means of a DC-notch filter.

6. The device of claim 4, wherein the DC-filtered signal is multiplied by a window function.

7. The device of claim 2, wherein the zero-phase spectrum represents a magnitude spectrum of the signal.

8. The device of claim 7, wherein the magnitude spectrum of the signal is compressed to a compressed spectrum.

9. The device of claim 2, wherein the spectrum of the signal is windowed by means of a window function.

10. The device of n claim 2, wherein the transformation of the zero-phase spectrum of the signal comprises an Inverse Fourier Transformation.

11. The device of claim 2, wherein the correlation signal is attenuated by means of a window function.

12. The device of claim 2, wherein the combination of the spectrum and the correlation signal comprises resampling of at least one of the spectrum or the correlation signal.

13. The device of claim 2, wherein the estimating of the pitch pattern, by the processing system, comprises searching for an absolute maximum of the combined signal.

14. The device of claim 2, wherein the signal is rectified by a full-wave rectification function.

15. The device of claim 14, wherein a zero-phase spectrum of the rectified signal is compared with the zero-phase spectrum of the non-rectified signal and wherein the maximum of these signals is combined with the correlation signal to form the combined signal.

3. A non-transitory memory, the memory modified by encoding with a computer code, the computer code causing a computer to carry out the method of:

transforming, by the computer, the signal from a time-domain to a frequency-domain to obtain a spectrum of the signal,

processing, by the computer, the spectrum to obtain a zero-phase spectrum of the signal,

transforming, by the computer, a positive portion of the zero-phase spectrum of the signal to the time-domain to obtain a correlation signal,

multiplying, by the computer, the spectrum and the correlation signal to a combined spectrum, and

estimating, by the computer, the pitch pattern of the signal based on the combined spectrum.