FR2326805A1 - Pulse code modulation circuit for telephone applications - provides high signal to noise ratio using ramped analogue technique - Google Patents

Pulse code modulation circuit for telephone applications - provides high signal to noise ratio using ramped analogue technique

Info

Publication number
FR2326805A1
FR2326805A1 FR7529844A FR7529844A FR2326805A1 FR 2326805 A1 FR2326805 A1 FR 2326805A1 FR 7529844 A FR7529844 A FR 7529844A FR 7529844 A FR7529844 A FR 7529844A FR 2326805 A1 FR2326805 A1 FR 2326805A1
Authority
FR
France
Prior art keywords
noise ratio
ramped
modulation circuit
high signal
provides high
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.)
Withdrawn
Application number
FR7529844A
Other languages
French (fr)
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.)
SOUBIES CAMY HENRI
Original Assignee
SOUBIES CAMY HENRI
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 SOUBIES CAMY HENRI filed Critical SOUBIES CAMY HENRI
Priority to FR7529844A priority Critical patent/FR2326805A1/en
Publication of FR2326805A1 publication Critical patent/FR2326805A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M1/00—Analogue/digital conversion; Digital/analogue conversion
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M1/00—Analogue/digital conversion; Digital/analogue conversion
    • H03M1/12—Analogue/digital converters
    • H03M1/50—Analogue/digital converters with intermediate conversion to time interval

Landscapes

  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Compression, Expansion, Code Conversion, And Decoders (AREA)

Abstract

A coding circuit for telephone communications systems uses PCM techniques where amplitude compression is used following normalised characteristics to improve the signal to noise ratio at low transmission levels. A reference voltage is compared against sampled sections of the unknown level transmission resulting in an 'anamorph' of the normalised coding characteristics and consists of a unique ramp of eight successive slopes (Sk) between zero and a maximum level, this being >= the highest level occuring in the sample. Each of the four final slopes has twice the duration of each of the first two. A pulse counter processing the code is fed by a variable oscillator whose frequency falls to half value during the period of one sample segment.
FR7529844A 1975-09-30 1975-09-30 Pulse code modulation circuit for telephone applications - provides high signal to noise ratio using ramped analogue technique Withdrawn FR2326805A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
FR7529844A FR2326805A1 (en) 1975-09-30 1975-09-30 Pulse code modulation circuit for telephone applications - provides high signal to noise ratio using ramped analogue technique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7529844A FR2326805A1 (en) 1975-09-30 1975-09-30 Pulse code modulation circuit for telephone applications - provides high signal to noise ratio using ramped analogue technique

Publications (1)

Publication Number Publication Date
FR2326805A1 true FR2326805A1 (en) 1977-04-29

Family

ID=9160622

Family Applications (1)

Application Number Title Priority Date Filing Date
FR7529844A Withdrawn FR2326805A1 (en) 1975-09-30 1975-09-30 Pulse code modulation circuit for telephone applications - provides high signal to noise ratio using ramped analogue technique

Country Status (1)

Country Link
FR (1) FR2326805A1 (en)

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