JPS57143906A - Fm demodulator for composite modulation system - Google Patents

Fm demodulator for composite modulation system

Info

Publication number
JPS57143906A
JPS57143906A JP56029334A JP2933481A JPS57143906A JP S57143906 A JPS57143906 A JP S57143906A JP 56029334 A JP56029334 A JP 56029334A JP 2933481 A JP2933481 A JP 2933481A JP S57143906 A JPS57143906 A JP S57143906A
Authority
JP
Japan
Prior art keywords
signal
frequency
wave
monitoring control
demodulator
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.)
Pending
Application number
JP56029334A
Other languages
Japanese (ja)
Inventor
Kazuo Ogawa
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.)
Fujitsu Ltd
Original Assignee
Fujitsu 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 Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP56029334A priority Critical patent/JPS57143906A/en
Publication of JPS57143906A publication Critical patent/JPS57143906A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D3/00—Demodulation of angle-, frequency- or phase- modulated oscillations
    • H03D3/007—Demodulation of angle-, frequency- or phase- modulated oscillations by converting the oscillations into two quadrature related signals

Abstract

PURPOSE:To extract only a monitoring control signal by processing a base band signal by using a local oscillator, whose frequency is nearly equal to an input signal frequency, for the phase detection of a signal which contains a PSK wave as a main signal and an FM-modulated wave as the monitoring control signal. CONSTITUTION:A signal containing an (n)-phase PSK wave as a main signal and an FM-modulated wave as a monitoring control signal is repeated on heterodyne basis by the microwave circuits 11a and 11b, and intermediate-frequency-wave circuits 12a and 12b of a main repeating station. A signal inputted to an FM demodulator 13 is detected by a carrier 90 deg. out of phase with the output of a local oscillator 19 having a frequency nearly equal to an input signal frequency. Then, it is inputted to a base band processing circuit 16 to be multiplied by two, and the resulting signal is added to the output of differentiation 17 at a section 18 to pass the sum through an LPF20, thus extracting the monitoring control signal. On the other hand, the monitoring signal component is eliminated by using an LPF21 to achieve the follow-up control of the oscillator 19, thereby obtaining a demodulator which eliminates the need for phase synchronization.
JP56029334A 1981-03-03 1981-03-03 Fm demodulator for composite modulation system Pending JPS57143906A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56029334A JPS57143906A (en) 1981-03-03 1981-03-03 Fm demodulator for composite modulation system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56029334A JPS57143906A (en) 1981-03-03 1981-03-03 Fm demodulator for composite modulation system

Publications (1)

Publication Number Publication Date
JPS57143906A true JPS57143906A (en) 1982-09-06

Family

ID=12273329

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56029334A Pending JPS57143906A (en) 1981-03-03 1981-03-03 Fm demodulator for composite modulation system

Country Status (1)

Country Link
JP (1) JPS57143906A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02277328A (en) * 1989-04-18 1990-11-13 Fujitsu Ltd Auxiliary signal transmission system
US5530406A (en) * 1992-11-30 1996-06-25 Alcatel Standard Electrica S.A. Frequency synthesizer having a phase-locked loop structure for fast generation of radio-frequency channels

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02277328A (en) * 1989-04-18 1990-11-13 Fujitsu Ltd Auxiliary signal transmission system
US5530406A (en) * 1992-11-30 1996-06-25 Alcatel Standard Electrica S.A. Frequency synthesizer having a phase-locked loop structure for fast generation of radio-frequency channels

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