GB1356649A - Speech transmission system - Google Patents

Speech transmission system

Info

Publication number
GB1356649A
GB1356649A GB5993271A GB5993271A GB1356649A GB 1356649 A GB1356649 A GB 1356649A GB 5993271 A GB5993271 A GB 5993271A GB 5993271 A GB5993271 A GB 5993271A GB 1356649 A GB1356649 A GB 1356649A
Authority
GB
United Kingdom
Prior art keywords
filter
signal
speech
output
adaptive
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB5993271A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
STC PLC
Original Assignee
Standard Telephone and Cables PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to GB5993271A priority Critical patent/GB1356649A/en
Priority to FR7245703A priority patent/FR2164813B3/fr
Priority to ES409984A priority patent/ES409984A1/en
Publication of GB1356649A publication Critical patent/GB1356649A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H21/00—Adaptive networks
    • H03H21/0012—Digital adaptive filters
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10L—SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING
    • G10L19/00—Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10L—SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING
    • G10L19/00—Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis
    • G10L19/04—Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis using predictive techniques
    • G10L19/06—Determination or coding of the spectral characteristics, e.g. of the short-term prediction coefficients

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Audiology, Speech & Language Pathology (AREA)
  • Computational Linguistics (AREA)
  • Signal Processing (AREA)
  • Health & Medical Sciences (AREA)
  • Human Computer Interaction (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Transmission Systems Not Characterized By The Medium Used For Transmission (AREA)
  • Filters That Use Time-Delay Elements (AREA)
  • Compression, Expansion, Code Conversion, And Decoders (AREA)

Abstract

1356649 Speech transmission systems STANDARD TELEPHONES & CABLES Ltd 23 Dec 1971 59932/71 Heading H4R In a speech transmission system a self adaptive filter 1 is connected in a negative feed forward configuration in the speech path with the speech input signal for the filter also connected to the filter as the target signal, and the filter output being subtracted at 2 from the speech input signal to provide a residual signal output, from which the excitation function signal can be extracted. The excitation function signal and the multiplier coefficients of the adaptive filter are coded and transmitted to the receiver where the signals are decoded and fed to an excitation generator, to provide the input, and the multiplier adjustments of, an adaptive filter 9 connected in a positive feedback configuration, so that the original speech is available at the output of adder 10. In an alternative embodiment, Fig. 3, a decoder 24, 25, is incorporated in the transmitter with the adaptive filters 24, 23 of the decoders in the transmitter and the receiver both fed with an error signal derived by comparison of the output of filter 28, whose multipliers are directly coupled to the multipliers in the self adaptive filter 29, with the output of filter 24, so that the multipliers of filter 24, and hence filter 23, are continuously adjusted to be the same as those of filter 28 and hence filter 29, with the coder and decoders in the adjustment loop so that compensation is provided for quantizing errors &c. The excitation function signal and the multiplier coefficients, or error signal in the embodiment of Fig. 3, are slowly varying functions allowing low speed sampling for transmission. Since it is possible for the sampling to be of the same order as the resonance period of the input signal the sampling interval is made to vary in a pseudo random fashion. The adaptive filters are convention transversal filters with the self adaptive filter being described with respect to Fig. 2 (not shown).
GB5993271A 1971-12-23 1971-12-23 Speech transmission system Expired GB1356649A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
GB5993271A GB1356649A (en) 1971-12-23 1971-12-23 Speech transmission system
FR7245703A FR2164813B3 (en) 1971-12-23 1972-12-21
ES409984A ES409984A1 (en) 1971-12-23 1972-12-22 Speech transmission system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB5993271A GB1356649A (en) 1971-12-23 1971-12-23 Speech transmission system

Publications (1)

Publication Number Publication Date
GB1356649A true GB1356649A (en) 1974-06-12

Family

ID=10484681

Family Applications (1)

Application Number Title Priority Date Filing Date
GB5993271A Expired GB1356649A (en) 1971-12-23 1971-12-23 Speech transmission system

Country Status (3)

Country Link
ES (1) ES409984A1 (en)
FR (1) FR2164813B3 (en)
GB (1) GB1356649A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2130055A (en) * 1982-11-05 1984-05-23 Stc Plc A digital speech transmission system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2130055A (en) * 1982-11-05 1984-05-23 Stc Plc A digital speech transmission system

Also Published As

Publication number Publication date
FR2164813A1 (en) 1973-08-03
ES409984A1 (en) 1976-01-01
FR2164813B3 (en) 1976-02-13

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Legal Events

Date Code Title Description
PS Patent sealed
PLNP Patent lapsed through nonpayment of renewal fees