CA1197619A
Expired / Lapsed
CA
⏱️ 0.0 years remaining
Voice encoding systems
Assignee: NEC Corp
•
Filing: 1983-12-23
•
Granted: 1985-12-03
•
Expires: 2003-12-23
Abstract
Abstract Abstract of the Disclosure A voice encoding system is constituted by a short time voice signal series producing circuit inputted with a discrete voice signal series for dividing the same at each short time; a parameter extracting circuit for extracting a parameter representative of a spectrum envelope from the short time voice signal series and encoding the parameter; an impulse response series calculating circuit for calculating the impulse response series based on the parameter representative of the spectrum envelope; an autocorrelation function sequence calculating circuit utilizing the impulse response series; a cross-correlation function sequence calculating circuit utilizing the impulse response series and the short time voice singl series; a circuit for calculating and encoding an excitation signal series of the short time voice signal series by utilizing the autocorrelation function sequence; and a circuit for combining and outputting a code of the parameter representative of the spectrum envelope and a code representative of the excitation signal series. With the system, high quality voice encoding can be made at a transmission rate of less than 10K bits/second with a relatively small amount of calculation.
Inventors
- 👤 Kazunori Ozawa
- 👤 Takashi Araseki
Bibliographic Details
Application Number
—
Jurisdiction
CA
Data Source
google_patents
Last Synchronized
2026-11-01 11:27
CPC Classifications
G; G10; G10L; G10L19/00; G10L19/04; G10L19/08; G10L19/10
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
152 words
A voice encoding system comprising: means inputted with a discrete voice signal series for dividing said voice signal series at each short time to obtain a short time voice signal series; means for extracting a parameter representative of a spectrum envelope from said short time voice signal series and encoding the parameter; means for calculating an impulse response series based on said parameter representative of said spectrum envelope; means for calculating an autocorrelation funtion sequence by using said impulse response series; means for calculating a cross-correlation function sequence by using said impulse response series and said short time voice signal series; means for calculating and encoding an excitation signal series of said short time voice signal series by using said autocorrelation function sequence and said cross-correlation function sequence; and means for combining and outputting a code of said parameter represntative of said spectrum envelope and a code representative said excitation signal series.
Claim 2
Dependent Claim
152 words
A voice encoding system comprising: means inputted with a discrete voice signal series for dividing said voice signal series at each short time to obtain a short time voice signal series; means for extracting a parameter representative of a spectrum envelope from said short time voice signal series and encoding the parameter; means for calculating an impulse response series based on said parameter representative of said spectrum envelope; means for calculating an autocorrelation funtion sequence by using said impulse response series; means for calculating a cross-correlation function sequence by using said impulse response series and said short time voice signal series; means for calculating and encoding an excitation signal series of said short time voice signal series by using said autocorrelation function sequence and said cross-correlation function sequence; and means for combining and outputting a code of said parameter represntative of said spectrum envelope and a code representative said excitation signal series.
Claim 3
Dependent Claim
174 words
A voice encoding system comprising: means inputted with a discrete voice signal series for dividing said voice signal series at each short time to obtain a short time voice signal series; means for extracting a parameter representative of a spectrum envelope from said short time voice signal series and encoding the parameter; means for calculating an impulse response series based on said parameter representative of said spectrum envelope; means for calculating an autocorrelation function sequence by using said impulse response series; means for calculating a target signal series which has been subjected to a predetermined correction based on said short time voice signal series; means for calculating a cross-correlation function sequence by using said impulse response series and said target signal series; means for calculating and encoding an excitation signal series of said short time voice signal series by using said autocorrelation function series and said cross-correlation function series; and means for combinaing and outputting a code of said parameter representative of said spectrum envelope and a code representative of said excitation signal series.
Claim 4
Dependent Claim
174 words
A voice encoding system comprising: means inputted with a discrete voice signal series for dividing said voice signal series at each short time to obtain a short time voice signal series; means for extracting a parameter representative of a spectrum envelope from said short time voice signal series and encoding the parameter; means for calculating an impulse response series based on said parameter representative of said spectrum envelope; means for calculating an autocorrelation function sequence by using said impulse response series; means for calculating a target signal series which has been subjected to a predetermined correction based on said short time voice signal series; means for calculating a cross-correlation function sequence by using said impulse response series and said target signal series; means for calculating and encoding an excitation signal series of said short time voice signal series by using said autocorrelation function series and said cross-correlation function series; and means for combinaing and outputting a code of said parameter representative of said spectrum envelope and a code representative of said excitation signal series.
Claim 5
Independent Claim
275 words
A method of encoding a voice comprising the steps of: inputting a discrete voice signal series on a transmission side; subtracting a response signal series originating from a previously determined excitation signal series from said voice signal series; extracting and encoding a parameter representative of said voice signal series or a short time spectrum envelope of the result of said subtraction; determining an impulse response series based on the parameter representative of said spectrum envelope and calculating an autocorrelation function sequence of said impulse response series; forming a target signal series based on the result of said subtraction and calculating a cross-correlation function sequence between said target signal series and said impulse response series; searching and encoding an excitation signal series of said voice signal series by using said autocorrelation function sequence and said cross-correlation function sequence; forming a response signal series originating from said excitation signal series; combining and outputting a code series of parameter representative of said spectrum envelope and a code series of said excitation signal series; inputting said code series on a receiving side 3 and separating said code series of said excitation signal series and said code series of said parameter representative of said spectrum envelope; decoding said excitation signal series from said separated code series for producing an excitation pulse series; synthesizing said voice signal series by using a parameter representative of a spectrum envelope decoded from said separated code series of said inputted excitation pulse series; and calculating a response signal series originating from said excitation pulse series and adding together said response signal series and said synthesized voice signal series to output the result of said addition.
Claim 6
Independent Claim
275 words
A method of encoding a voice comprising the steps of: inputting a discrete voice signal series on a transmission side; subtracting a response signal series originating from a previously determined excitation signal series from said voice signal series; extracting and encoding a parameter representative of said voice signal series or a short time spectrum envelope of the result of said subtraction; determining an impulse response series based on the parameter representative of said spectrum envelope and calculating an autocorrelation function sequence of said impulse response series; forming a target signal series based on the result of said subtraction and calculating a cross-correlation function sequence between said target signal series and said impulse response series; searching and encoding an excitation signal series of said voice signal series by using said autocorrelation function sequence and said cross-correlation function sequence; forming a response signal series originating from said excitation signal series; combining and outputting a code series of parameter representative of said spectrum envelope and a code series of said excitation signal series; inputting said code series on a receiving side 3 and separating said code series of said excitation signal series and said code series of said parameter representative of said spectrum envelope; decoding said excitation signal series from said separated code series for producing an excitation pulse series; synthesizing said voice signal series by using a parameter representative of a spectrum envelope decoded from said separated code series of said inputted excitation pulse series; and calculating a response signal series originating from said excitation pulse series and adding together said response signal series and said synthesized voice signal series to output the result of said addition.
Claim 7
Dependent Claim
220 words
An encoding system comprising: a subtracting circuit inputted with a discrete voice signal series and subtracting a response signal series from said voice signal series; a parameter calculating circuit extracting and encoding a parameter representative of said voice signal series or a short time spectrum envelope of the output series of said subtracting circuit; an impulse response series calculating circuit for calculating an impulse response series based on said parameter representative of said spectrum envelope; an autocorrelation function sequence calculating circuit inputted with the output series of said impulse response series calculating circuit for calculating an autocorrelation function sequence; a cross-correlation function calculating circuit for calculating a cross-correlation function sequence between the output series of said subtracting circuit or a signal obtained by subjecting said output series of said subtracting circuit to a predetermined correction and said impulse response series; an excitation signal series calculating circuit inputted with said autocorrelation function sequence and said cross-correlation function sequence for calculating and encoding said excitation signal series of said voice signal series; a response signal series calculating circuit inputted with said excitation signal series for calculating said response signal series originating from said excitation signal series; and a multiplexer circuit for combining and outputting the output code series of said parameter calculating circuit and the code series of said excitation signal series.
Claim 8
Dependent Claim
220 words
An encoding system comprising: a subtracting circuit inputted with a discrete voice signal series and subtracting a response signal series from said voice signal series; a parameter calculating circuit extracting and encoding a parameter representative of said voice signal series or a short time spectrum envelope of the output series of said subtracting circuit; an impulse response series calculating circuit for calculating an impulse response series based on said parameter representative of said spectrum envelope; an autocorrelation function sequence calculating circuit inputted with the output series of said impulse response series calculating circuit for calculating an autocorrelation function sequence; a cross-correlation function calculating circuit for calculating a cross-correlation function sequence between the output series of said subtracting circuit or a signal obtained by subjecting said output series of said subtracting circuit to a predetermined correction and said impulse response series; an excitation signal series calculating circuit inputted with said autocorrelation function sequence and said cross-correlation function sequence for calculating and encoding said excitation signal series of said voice signal series; a response signal series calculating circuit inputted with said excitation signal series for calculating said response signal series originating from said excitation signal series; and a multiplexer circuit for combining and outputting the output code series of said parameter calculating circuit and the code series of said excitation signal series.
Claim 9
Dependent Claim
221 words
A decoding apparatus comprising: a subtractor subtracting a response signal series originating from an excitation signal series obtained previously from a discrete voice signal series; a first encoder extracting and encoding a parameter representative of said voice signal series or a short time spectrum envelope of the result of subtraction; a second encoder searching and encoding an excitation signal series by using a cross-correlation function sequence calculated based on an impulse response series obtained from said parameter and said result of subtraction and using an autocorrelation function sequence calculated based on said impulse response series; a demultiplexer circuit inputted with a code series formed by combining an output code series of a parameter calculating circuit and a code series of said excitation signal series for separating a code series representative of said excitation signal series and a code series of a parameter representative of said spectrum envelope; an excitation pulse series generating circuit for decoding said separated code series representative of said excitation signal series for generating an excitation series; a decoding circuit for decoding said separated code series of said parameter representative of said spectrum envelope; and a synthesizing filter circuit inputted with the output series of said excitation pulse series generating circuit for synthesizing and outputting a voice signal series by using the output parameter of said decoding circuit.
Claim 10
Dependent Claim
221 words
A decoding apparatus comprising: a subtractor subtracting a response signal series originating from an excitation signal series obtained previously from a discrete voice signal series; a first encoder extracting and encoding a parameter representative of said voice signal series or a short time spectrum envelope of the result of subtraction; a second encoder searching and encoding an excitation signal series by using a cross-correlation function sequence calculated based on an impulse response series obtained from said parameter and said result of subtraction and using an autocorrelation function sequence calculated based on said impulse response series; a demultiplexer circuit inputted with a code series formed by combining an output code series of a parameter calculating circuit and a code series of said excitation signal series for separating a code series representative of said excitation signal series and a code series of a parameter representative of said spectrum envelope; an excitation pulse series generating circuit for decoding said separated code series representative of said excitation signal series for generating an excitation series; a decoding circuit for decoding said separated code series of said parameter representative of said spectrum envelope; and a synthesizing filter circuit inputted with the output series of said excitation pulse series generating circuit for synthesizing and outputting a voice signal series by using the output parameter of said decoding circuit.
Claim 11
Dependent Claim
220 words
A voice encoding system comprising: means inputted with a discrete voice signal series for sectionalizing the same while shifting it by a predetermined sample number; means for subtracting from said sectionalized voice signal series a response sigal series originating from an excitation signal series calculated beforehand; means for extracting and encoding a parameter representative of a short time spectrum envelope by using said sectionalized voice signal series or an output series of said subtracting means; means for calculating an impulse response series based on said parameter representative of said short time spectrum envelope; means for calculating an autocorrelation funtion sequence by using said impulse response series; means inputted with said output series of said subtracting means and said impulse response series for calculating a cross-correlation function sequence between the output series of said subtracting means or a signal obtained by subjecting the output series of said subtracting means to a predetermined correction and said impulse response series; means for determining and encoding an excitation source signal series for a voice signal series of a smaller sample number than said sectionalized voice signal series by using said autocorrelation function sequence and said cross-correlation function sequence; and means for combining and outputting a code of a parameter representative of said short time spectrum envelope and a code representative said excitation signal series.
Claim 12
Dependent Claim
220 words
A voice encoding system comprising: means inputted with a discrete voice signal series for sectionalizing the same while shifting it by a predetermined sample number; means for subtracting from said sectionalized voice signal series a response sigal series originating from an excitation signal series calculated beforehand; means for extracting and encoding a parameter representative of a short time spectrum envelope by using said sectionalized voice signal series or an output series of said subtracting means; means for calculating an impulse response series based on said parameter representative of said short time spectrum envelope; means for calculating an autocorrelation funtion sequence by using said impulse response series; means inputted with said output series of said subtracting means and said impulse response series for calculating a cross-correlation function sequence between the output series of said subtracting means or a signal obtained by subjecting the output series of said subtracting means to a predetermined correction and said impulse response series; means for determining and encoding an excitation source signal series for a voice signal series of a smaller sample number than said sectionalized voice signal series by using said autocorrelation function sequence and said cross-correlation function sequence; and means for combining and outputting a code of a parameter representative of said short time spectrum envelope and a code representative said excitation signal series.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.