FR2369738A1 - Dispositif de demodulation synchrone et poste telephonique utilisant un tel dispositif - Google Patents

Dispositif de demodulation synchrone et poste telephonique utilisant un tel dispositif

Info

Publication number
FR2369738A1
FR2369738A1 FR7632715A FR7632715A FR2369738A1 FR 2369738 A1 FR2369738 A1 FR 2369738A1 FR 7632715 A FR7632715 A FR 7632715A FR 7632715 A FR7632715 A FR 7632715A FR 2369738 A1 FR2369738 A1 FR 2369738A1
Authority
FR
France
Prior art keywords
parallel
differential amplifiers
synchronous demodulator
fed
switched telephone
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Withdrawn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
FR7632715A
Other languages
English (en)
Inventor
Rene Lechevin
Roger Granek
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.)
Thales SA
Original Assignee
Thomson CSF SA
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 Thomson CSF SA filed Critical Thomson CSF SA
Priority to FR7632715A priority Critical patent/FR2369738A1/fr
Publication of FR2369738A1 publication Critical patent/FR2369738A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D1/00—Demodulation of amplitude-modulated oscillations
    • H03D1/22—Homodyne or synchrodyne circuits
    • H03D1/2245—Homodyne or synchrodyne circuits using two quadrature channels
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/42—Systems providing special services or facilities to subscribers
    • H04M3/56—Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities
    • H04M3/561—Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities by multiplexing

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Power Engineering (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)

Abstract

La présente invention concerne les moyens de s'affranchir de la nécessité d'une mise en phase des signaux appliqués aux démodulateurs synchrones, notamment ceux utilises dans des postes téléphoniques à modulation d'amplitude à double bande. L'invention consiste à additionner (ou à soustraire) les signaux de sortie issus respectivement de deux démodulateurs alimentés en parallèle par le signal à démoduler et en quadrature de phase par un générateur de porteuse locale, après leur avoir fait subir un déphasage les décalant entre eux d'une valeur égale à pi /2 pour chaque composante de fréquence du spectre de modulation transmis, afin de rendre l'amplitude du signal démodulé indépendante de la phase relative des porteuses des signaux reçus et localement générés. Application aux postes téléphoniques à démodulation synchrone des systèmes à commutation fréquentielle.
FR7632715A 1976-10-29 1976-10-29 Dispositif de demodulation synchrone et poste telephonique utilisant un tel dispositif Withdrawn FR2369738A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
FR7632715A FR2369738A1 (fr) 1976-10-29 1976-10-29 Dispositif de demodulation synchrone et poste telephonique utilisant un tel dispositif

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7632715A FR2369738A1 (fr) 1976-10-29 1976-10-29 Dispositif de demodulation synchrone et poste telephonique utilisant un tel dispositif

Publications (1)

Publication Number Publication Date
FR2369738A1 true FR2369738A1 (fr) 1978-05-26

Family

ID=9179385

Family Applications (1)

Application Number Title Priority Date Filing Date
FR7632715A Withdrawn FR2369738A1 (fr) 1976-10-29 1976-10-29 Dispositif de demodulation synchrone et poste telephonique utilisant un tel dispositif

Country Status (1)

Country Link
FR (1) FR2369738A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0014044A1 (fr) * 1979-01-18 1980-08-06 Rolm Corporation Procédé et dispositif pour réduire les oscillations dans un pont de conférence

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0014044A1 (fr) * 1979-01-18 1980-08-06 Rolm Corporation Procédé et dispositif pour réduire les oscillations dans un pont de conférence

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Legal Events

Date Code Title Description
ST Notification of lapse