JPS57181210A - Demodulation system - Google Patents

Demodulation system

Info

Publication number
JPS57181210A
JPS57181210A JP6643882A JP6643882A JPS57181210A JP S57181210 A JPS57181210 A JP S57181210A JP 6643882 A JP6643882 A JP 6643882A JP 6643882 A JP6643882 A JP 6643882A JP S57181210 A JPS57181210 A JP S57181210A
Authority
JP
Japan
Prior art keywords
carrier
triangular wave
facsimile signal
frequency
triangular
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.)
Granted
Application number
JP6643882A
Other languages
Japanese (ja)
Other versions
JPS6220732B2 (en
Inventor
Masahiro Furuya
Shigemichi Maeda
Hideo Nakazawa
Yasuhiro Kita
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.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP6643882A priority Critical patent/JPS57181210A/en
Publication of JPS57181210A publication Critical patent/JPS57181210A/en
Publication of JPS6220732B2 publication Critical patent/JPS6220732B2/ja
Granted 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Facsimile Image Signal Circuits (AREA)

Abstract

PURPOSE:To achieve demodulation without increasing a sampling frequency by using a triangular wave as a carrier for synchronous detection. CONSTITUTION:A triangular wave is used as a carrier for synchronous detection. When this triangular wave is processed by Fourier series expansion, higher hamonics are reduced in order of 1/(n<2>). Thus, less-distortion demodulation is achieved without increasing a scampling frequency. In concrete, a transmitted modulated facsimile signal 5 while applied directly to a demodulator 4 is branched and inputted to a digital PLL1, which sends a carrier component signal 6 to a triangular wave generator 9 to regenerate a triangular-wave carrier 10 having a prescribed frequency, which is applied to the demodulator 4. The regenerated carrier 10 is multiplied by the directly-inputted modulated facsimile signal 5, thereby sending out a demodulated facsimile signal 11.
JP6643882A 1982-04-20 1982-04-20 Demodulation system Granted JPS57181210A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6643882A JPS57181210A (en) 1982-04-20 1982-04-20 Demodulation system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6643882A JPS57181210A (en) 1982-04-20 1982-04-20 Demodulation system

Publications (2)

Publication Number Publication Date
JPS57181210A true JPS57181210A (en) 1982-11-08
JPS6220732B2 JPS6220732B2 (en) 1987-05-08

Family

ID=13315772

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6643882A Granted JPS57181210A (en) 1982-04-20 1982-04-20 Demodulation system

Country Status (1)

Country Link
JP (1) JPS57181210A (en)

Also Published As

Publication number Publication date
JPS6220732B2 (en) 1987-05-08

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