JPS5752251A - Demodulating equipment for unbalanced four-phase modulated wave - Google Patents

Demodulating equipment for unbalanced four-phase modulated wave

Info

Publication number
JPS5752251A
JPS5752251A JP12597480A JP12597480A JPS5752251A JP S5752251 A JPS5752251 A JP S5752251A JP 12597480 A JP12597480 A JP 12597480A JP 12597480 A JP12597480 A JP 12597480A JP S5752251 A JPS5752251 A JP S5752251A
Authority
JP
Japan
Prior art keywords
phase
carrier wave
output
demodulators
circuit
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
JP12597480A
Other languages
Japanese (ja)
Inventor
Yoshihiko Hishida
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 JP12597480A priority Critical patent/JPS5752251A/en
Publication of JPS5752251A publication Critical patent/JPS5752251A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
    • H04L27/22—Demodulator circuits; Receiver circuits
    • H04L27/227—Demodulator circuits; Receiver circuits using coherent demodulation
    • H04L27/2275—Demodulator circuits; Receiver circuits using coherent demodulation wherein the carrier recovery circuit uses the received modulated signals

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)

Abstract

PURPOSE:To exactly demodulate 2 kinds of data of an unbalanced four-phase modulation, by detecting a variation of a frequency component appearing in a demodulation output of 2 data whose speed is different, and locking the phase of a regenerative carrier wave. CONSTITUTION:A four-phase modulated wave from a terminal 1 is provided to phase demodulators 14, 15 and a synchronizing carrier wave regenerating circuit 16. In the circuit 16, a carrier wave synchronizing with the input signal is regenerated, and the carrier wave is supplied to the demodulator 14 and the demodulator 15 through a switching relay 22 and a pi/2 phase shifter 19, respectively. The demodulators 14, 15 demodulate data whose speed is different respectively, and output them to terminals 12, 13. LPFs 17, 18 transmit basic component of the base band spectrum of demodulated waves of the demodulators 14, 15, respectively, and supply them to a comparator 21, respectively. In case when the circuit 16 has the phase of the regenerative carrier wave locked to out-of-phase, output levels of the LPFs 17, 18 are different remarkably, an output is generated from the comparator 21, a relay 22 is switched, a pi/2 phase shifter 20 is inserted into an output of the circuit 16, and a carrier wave of correct phase is supplied to the demodulators 14, 15, by which demodulation is executed.
JP12597480A 1980-09-12 1980-09-12 Demodulating equipment for unbalanced four-phase modulated wave Pending JPS5752251A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP12597480A JPS5752251A (en) 1980-09-12 1980-09-12 Demodulating equipment for unbalanced four-phase modulated wave

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP12597480A JPS5752251A (en) 1980-09-12 1980-09-12 Demodulating equipment for unbalanced four-phase modulated wave

Publications (1)

Publication Number Publication Date
JPS5752251A true JPS5752251A (en) 1982-03-27

Family

ID=14923594

Family Applications (1)

Application Number Title Priority Date Filing Date
JP12597480A Pending JPS5752251A (en) 1980-09-12 1980-09-12 Demodulating equipment for unbalanced four-phase modulated wave

Country Status (1)

Country Link
JP (1) JPS5752251A (en)

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