System that detects and identifies periodic interference
View Patent ↗A system improves speech detection or processing by identifying registration signals. The system encodes a limited frequency band by varying the amplitude of a pulse width modulated signal between predefined values. The signal is separated into frequency bins that identify amplitude and phase. The registration signal is measured by comparing a difference in average acoustic power in a plurality of adjacent bins over time.
1. A process that improves speech processing by identifying periodic interference by processing a limited frequency band comprising:
converting a limited frequency band of a continuously varying input into a digital-domain signal;
converting the digital domain signal into a frequency-domain signal;
estimating the differences between a plurality of sets of adjacent frequency bins of the frequency-domain signal automatically;
comparing the estimated differences of the plurality of sets of adjacent frequency bins to a pre-programmed threshold automatically; and
identifying a periodic interference across an aural spectrum based on the comparison automatically in real time;
where the identification embeds a code in the continuously varying input.
2. A process that improves speech processing by identifying periodic interference by processing a limited frequency band comprising:
converting a limited frequency band of a continuously varying input into a digital-domain signal;
converting the digital domain signal into a frequency-domain signal;
estimating the differences between a plurality of sets of adjacent frequency bins of the frequency-domain signal automatically;
comparing the estimated differences of the plurality of sets of adjacent frequency bins to a pre-programmed threshold automatically; and
identifying a periodic interference across an aural spectrum based on the comparison automatically in real time;
where the identification comprises a time-varying signal in which its varying amplitude indicates a probability the periodic interference was detected.
3. A process that improves speech processing by identifying periodic interference by processing a limited frequency band comprising:
converting a limited frequency band of a continuously varying input into a digital-domain signal;
converting the digital domain signal into a frequency-domain signal;
estimating the differences between a plurality of sets of adjacent frequency bins of the frequency-domain signal automatically;
comparing the estimated differences of the plurality of sets of adjacent frequency bins to a pre-programmed threshold automatically;
identifying a periodic interference across an aural spectrum based on the comparison automatically in real time; and
deriving a probability that reflects the number of actual detections of the periodic interference to the number of possible occurrences during the limited frequency band.
4. A system that detects interference that is received with an unvoiced, a fully voiced, or a mixed voice input comprising:
a digital converter that converts a time-varying input signal into a digital-domain signal;
a window function configured to pass signals within a programmed aural frequency range while substantially blocking signals above and below the programmed aural frequency range when multiplied by an output of the digital converter;
a frequency converter that converts the signals passing within the programmed aural frequency range into a plurality of frequency bins;
a noise detector configured to compare the covariance of a plurality of adjacent frequency bins to a programmed threshold to determine when a periodic interference is present in the unvoiced, the fully voiced, or the mixed voice input automatically; and
a controller configured to derive a probability that reflects the number of actual detections of the periodic interference to the number of possible occurrences.
5. The system that detects interference that is received with the unvoiced, the fully voiced, or the mixed voice input of claim 4 further comprising a power domain converter configured to convert the output of the frequency domain into a power spectral domain.
6. The system that detects interference that is received with the unvoiced, the fully voiced, or the mixed voice input of claim 5 , where the power domain converter estimates the amplitude of each of the plurality of frequency bins through a weighted average.
7. The system that detects interference that is received with the unvoiced, the fully voiced, or the mixed voice input of claim 4 , where the noise detector is configured to set a flag that indicates when a registration signal occurs.
8. The system that detects interference that is received with the unvoiced, the fully voiced, or the mixed voice input of claim 4 , where the periodic interference comprises a Global System for Mobile Communication interference.
9. A system that detects a periodic interference that is received with an unvoiced, a fully voiced, or a mixed voice input comprising:
a digital converter that converts a time-varying input signal into a digital-domain signal;
a window function configured to pass signals within a programmed aural frequency range while substantially blocking signals above and below the frequency range when multiplied with an output of the digital converter;
a frequency converter that converts the signals passing within the programmed aural frequency range into a plurality of frequency bins;
a power domain converter that averages an acoustic power in each of the plurality of frequency bins;
a signal extractor that compares the spectral differences in selected frequency bins that comprise multiple peaks and troughs of the time-varying signal if viewed in the time domain; and
a noise identifier that automatically identifies the periodic interference;
where the noise identifier identifies the periodic interference by setting a flag that comprises a continuous signal in the time domain offset by a programmed increment
10. The system that detects a periodic interference that is received with an unvoiced, a fully voiced, or a mixed voice input of claim 9 further comprising probability logic that determines a confidence level of the identified periodic interference.