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US4410764A Expired / Lapsed US ⏱️ 0.0 years remaining

Speech processor for processing analog signals

Assignee: Boeing North American Inc
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Filing: 1981-06-29
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Granted: 1983-10-18
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Expires: 2001-06-29
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Abstract

Abstract Peak-limiting AGC for increased average power SSB transmission is improved by deriving a gain-control signal using Hilbert transform detection techniques to obtain a modulated envelope signal which is compared with a peak clipping reference to form the limiting gain-control signal.

Inventors

  • 👤 Willard F. Werth
  • 👤 Robert L. Craiglow

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 22:49
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/3036; H03G3/3042; H03G11/00; H03G3/3005

Claims Analysis

Total Claims: 22
Claim 1
Independent Claim 176 words
A speech processor for processing an analog signal comprising: gain control means for controlling the amplitude of the analog signal, the gain control means being controlled by a peak limited modulation envelope signal to provide a limited analog signal; Hilbert transformer means for performing a Hilbert transform on the limited analog signal to provide thereby an inphase signal and a quadrature phase signal; audio modulation detector means for detecting the peak limited modulation envelope signal, the audio modulation detector means includes a logic means for extracting the square root of the sum of the squares of the inphase signal and the quadrature phase signal to obtain thereby a peak limited signal, reference means for providing a peak reference signal, comparator means for comparing the peak reference signal with the peak limited signal to obtain an analog peak limited modulation signal thereby, and detector means for separating the peak limited modulation envelope signal from the analog peak limited modulation signal; and feedback path means for coupling the peak limited modulation envelope signal to the gain control means.
Claim 2
Dependent Claim 176 words
A speech processor for processing an analog signal comprising: gain control means for controlling the amplitude of the analog signal, the gain control means being controlled by a peak limited modulation envelope signal to provide a limited analog signal; Hilbert transformer means for performing a Hilbert transform on the limited analog signal to provide thereby an inphase signal and a quadrature phase signal; audio modulation detector means for detecting the peak limited modulation envelope signal, the audio modulation detector means includes a logic means for extracting the square root of the sum of the squares of the inphase signal and the quadrature phase signal to obtain thereby a peak limited signal, reference means for providing a peak reference signal, comparator means for comparing the peak reference signal with the peak limited signal to obtain an analog peak limited modulation signal thereby, and detector means for separating the peak limited modulation envelope signal from the analog peak limited modulation signal; and feedback path means for coupling the peak limited modulation envelope signal to the gain control means.
Claim 3
Dependent Claim 86 words
The speech processor according to claim 1, wherein the logic means comprises: a first squaring means for squaring the inphase analog signal to obtain a first squared signal; a second squaring means for squaring the quadrature phase signal to obtain a second squared signal; summing means for summing the first squared signal with the second squared signal to obtain a sum of the squares signal; and square root means for taking the square root of the sum of the squares signal to obtain limited signal thereby.
Claim 4
Dependent Claim 138 words
The speech processor according to claim 1, wherein the logic means comprises: first absolute value means for obtaining the absolute value of the inphase signal to obtain a first absolute signal; square means for squaring the first absolute signal to obtain a first absolute squared signal; second absolute value means for obtaining the absolute value of the quadrature phase signal to obtain, thereby a second absolute signal; 1st summing means for summing the second absolute signal with the peak limited signal to obtain a denominator signal; divider means for dividing the first absolute squared signal by the denominator signal to obtain thereby, a quotient signal; 2nd summing means for summing the quotient signal with the second absolute signal to obtain thereby, the peak limited signal; and feedback path means coupling the peak limited signal to the summing means.
Claim 5
Dependent Claim 28 words
The speech processor according to claim 1, further comprising: transducer means for transducing sound waves into the analog signal, the analog signal being representative of the sound waves.
Claim 6
Dependent Claim 18 words
The speech processor according to claim 1, further comprising: a radio transmitter means for transmitting the inphase signal.
Claim 7
Dependent Claim 201 words
A speech processor for processing an analog signal comprising: A Hilbert transformer means for performing a Hilbert transform on the analog signal to obtain thereby an inphase signal and a quadrature phase signal; 1st variable gain amplifier means for amplifying the inphase signal to obtain a limited inphase signal; 2nd variable gain amplifier means for amplifying the quadrature phase signal to obtain a limited quadrature phase signal; audio modulation detector means for detecting a peak limited modulation envelope signal, the audio modular detection means includes a logic means for extracting the square root of the sum of the squares of the inphase signal and the quadrature phase signal to obtain thereby a peak limited signal, reference means for providing a peak reference signal, comparator means for comparing the peak reference signal with the peak limited signal to obtain an analog peak limited modulation signal thereby, and detector means for separating the peak limited modulation envelope signal from the analog peak limited modulation signal; and feedback path means for coupling the peak limited modulation signal to the first and second variable gain amplifiers, the gain of the first and second variable gain amplifier being controlled by the peak limited modulation envelope signal.
Claim 8
Dependent Claim 201 words
A speech processor for processing an analog signal comprising: A Hilbert transformer means for performing a Hilbert transform on the analog signal to obtain thereby an inphase signal and a quadrature phase signal; 1st variable gain amplifier means for amplifying the inphase signal to obtain a limited inphase signal; 2nd variable gain amplifier means for amplifying the quadrature phase signal to obtain a limited quadrature phase signal; audio modulation detector means for detecting a peak limited modulation envelope signal, the audio modular detection means includes a logic means for extracting the square root of the sum of the squares of the inphase signal and the quadrature phase signal to obtain thereby a peak limited signal, reference means for providing a peak reference signal, comparator means for comparing the peak reference signal with the peak limited signal to obtain an analog peak limited modulation signal thereby, and detector means for separating the peak limited modulation envelope signal from the analog peak limited modulation signal; and feedback path means for coupling the peak limited modulation signal to the first and second variable gain amplifiers, the gain of the first and second variable gain amplifier being controlled by the peak limited modulation envelope signal.
Claim 9
Dependent Claim 110 words
The speech processor according to claim 6, wherein the logic means comprises: a first squaring means for squaring the inphase analog signal to obtain a first squared signal; a second squaring means for squaring the quadrature phase signal to obtain a second squared signal; summing means for summing the first squared signal with the first and second squared signal to obtain a sum of the squares signal; and square root means for taking the square root of the sum of the squares signal to obtain the square root of the sum of the squares of the inphase signal and the quadrature phase signal to obtain the peak limited signal thereby.
Claim 10
Dependent Claim 138 words
The speech processor according to claim 6, wherein the logic means comrises: first absolute value means for obtaining the absolute value of the inphase signal to obtain a first absolute signal; square means for squaring the first absolute signal to obtain a first absolute squared signal; second absolute value means for obtaining the absolute value of the quadrature phase signal to obtain thereby a second absolute signal; 1st summing means for summing the second absolute signal with the peak limited signal to obtain a denominator signal; divider means for dividing the denominator signal into the first absolute squared signal to obtain thereby a quotient signal; 2nd summing means for summing the quotient signal with the second absolute signal to obtain thereby the peak limited signal; and feedback means for coupling the peak limited signal to the summing means.
Claim 11
Dependent Claim 28 words
The speech processor according to claim 6, further comprising: transducer means for transducing sound waves into the analog signal, the analog signal being representative of the sound waves.
Claim 12
Dependent Claim 18 words
The speech processor according to claim 6, further comprising: a radio transmitter means for transmitting the inphase signal.
Claim 13
Independent Claim 163 words
A method of speech processing of an analog signal comprising: controlling the amplitude of the analog signal in response to a peak limited modulation envelope to obtain a limited analog signal; performing a Hilbert transform on the limited analog signal to provide thereby an inphase signal and a quadrature phase signal; and combining the inphase signal with the quadrature phase signal, said step of combining the inphase signal with the quadrature phase signal includes the steps of squaring the inphase signal, squaring the quadrature phase signal, summing the squared inphase signal with the squared quadrature phase signal, extracting the square root of the sum of the squares of the inphase signal and the quadrature phase signal to obtain thereby a peak limited signal, providing a peak limited reference signal, comparing the peak limited reference signal with the peak limited signal to obtain an analog peak limited modulation signal, and separating the peak limited modulation envelope signal from the analog peak limited modulation signal.
Claim 14
Independent Claim 163 words
A method of speech processing of an analog signal comprising: controlling the amplitude of the analog signal in response to a peak limited modulation envelope to obtain a limited analog signal; performing a Hilbert transform on the limited analog signal to provide thereby an inphase signal and a quadrature phase signal; and combining the inphase signal with the quadrature phase signal, said step of combining the inphase signal with the quadrature phase signal includes the steps of squaring the inphase signal, squaring the quadrature phase signal, summing the squared inphase signal with the squared quadrature phase signal, extracting the square root of the sum of the squares of the inphase signal and the quadrature phase signal to obtain thereby a peak limited signal, providing a peak limited reference signal, comparing the peak limited reference signal with the peak limited signal to obtain an analog peak limited modulation signal, and separating the peak limited modulation envelope signal from the analog peak limited modulation signal.
Claim 15
Dependent Claim 123 words
The method of speech processing according to claim 11, wherein the step of mathematically combining the inphase signal with the quadrature phase signal and detecting the peak limited modulation envelope signal comprises: obtaining the absolute value of the inphase signal to obtain a first absolute signal; squaring the first absolute signal to obtain a first absolute squared signal; obtaining the absolute value of the quadrature phase signal to obtain thereby a second absolute signal; summing the second absolute signal with the peak limited signal to obtain a denominator signal; and dividing the denominator signal into the first absolute squared signal to obtain thereby a quotient signal; and summing the second absolute signal with the quotient signal to obtain thereby the peak limited signal.
Claim 16
Dependent Claim 26 words
The method of speech processing according to claim 11, further comprising the step of: transducing sound waves into an analog signal representative of the sound waves.
Claim 17
Dependent Claim 18 words
The method of speech processing according to claim 11, further comprising, the step of: transmitting the inphase signal.
Claim 18
Independent Claim 200 words
A method of speech processing for processing an analog signal comprising the steps of: performing a Hilbert transform on the analog signal to obtain thereby an inphase signal and a quadrature phase signal; amplifying with a 1st variable gain amplifier the inphase signal to obtain a limited inphase signal; amplifying with a 2nd variable gain amplifier the quadrature phase signal to obtain a limited quadrature phase signal; combining the limited inphase signal with the limited quadrature phase signal, the step of combining of the inphase signal with the quadrature phase signal includes the steps of squaring the inphase signal, squaring the quadrature phase signal, summing the squared inphase signal with the squared quadrature phase signal, extracting the square root of the sum of the squares of the inphase signal and the quadrature phase signal to obtain thereby a peak limited signal, providing a peak limited reference signal, comparing the peak limited reference signal with the peak limited signal to obtain an analog peak limited modulation signal, and separating the peak limited modulation envelope signal from the analog peak limited modulation signal, the gain of the first and second variable gain amplifier being controlled by the peak limited modulation envelope signal.
Claim 19
Independent Claim 200 words
A method of speech processing for processing an analog signal comprising the steps of: performing a Hilbert transform on the analog signal to obtain thereby an inphase signal and a quadrature phase signal; amplifying with a 1st variable gain amplifier the inphase signal to obtain a limited inphase signal; amplifying with a 2nd variable gain amplifier the quadrature phase signal to obtain a limited quadrature phase signal; combining the limited inphase signal with the limited quadrature phase signal, the step of combining of the inphase signal with the quadrature phase signal includes the steps of squaring the inphase signal, squaring the quadrature phase signal, summing the squared inphase signal with the squared quadrature phase signal, extracting the square root of the sum of the squares of the inphase signal and the quadrature phase signal to obtain thereby a peak limited signal, providing a peak limited reference signal, comparing the peak limited reference signal with the peak limited signal to obtain an analog peak limited modulation signal, and separating the peak limited modulation envelope signal from the analog peak limited modulation signal, the gain of the first and second variable gain amplifier being controlled by the peak limited modulation envelope signal.
Claim 20
Dependent Claim 130 words
The method of speech processing according to claim 15, wherein the steps of mathematically combining the inphase signal with the quadrature phase signal comprises: obtaining the absolute value of the inphase signal to obtain a first absolute signal; squaring the first absolute signal to obtain a first absolute squared signal; obtaining the absolute value of the quadrature phase signal to obtain thereby a second absolute signal; summing the second absolute signal with the peak limited modulation signal to obtain a denominator signal; dividing the denominator signal into the first absolute squared signal to obtain thereby the peak limited modulation signal; detecting the peak limited modulation envelope signal in the peak a quotient signal; and summing the second absolute signal with the quotient signal to obtain thereby the peak limited signal.
Claim 21
Dependent Claim 26 words
The method of speech processing according to claim 15, further comprising, the step of: transducing sound waves into an analog signal representative of the sound waves.
Claim 22
Dependent Claim 18 words
The method of speech processing according to claim 15, further comprising, the step of: transmitting the inphase signal.

References Cited (Backward Citations)

US3484556A Cited
US3789143A Cited
US4103239A Cited
US3970937A Cited
US4208548A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-10-17 1987-04-18 1987-10-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-10-17 1991-04-18 1991-10-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-10-17 1995-04-18 1995-10-18 $7700.00 Window Closed / Lapsed

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