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GB1172975A - Improvements in or relating to Demodulation Systems - Google Patents

Improvements in or relating to Demodulation Systems

Info

Publication number
GB1172975A
GB1172975A GB843569A GB843569A GB1172975A GB 1172975 A GB1172975 A GB 1172975A GB 843569 A GB843569 A GB 843569A GB 843569 A GB843569 A GB 843569A GB 1172975 A GB1172975 A GB 1172975A
Authority
GB
United Kingdom
Prior art keywords
signal
filtered
circuit
multiplying
nov
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.)
Expired
Application number
GB843569A
Inventor
Ralph Bertrand Herman
William Renwick
Leonard Charles Walters
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.)
GE Healthcare UK Ltd
Plessey Co Ltd
Original Assignee
GE Healthcare UK Ltd
Plessey Co 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 GE Healthcare UK Ltd, Plessey Co Ltd filed Critical GE Healthcare UK Ltd
Priority to GB843569A priority Critical patent/GB1172975A/en
Priority claimed from GB49825/65A external-priority patent/GB1172974A/en
Publication of GB1172975A publication Critical patent/GB1172975A/en
Expired 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
    • H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
    • H04L27/14—Demodulator circuits; Receiver circuits
    • H04L27/144—Demodulator circuits; Receiver circuits with demodulation using spectral properties of the received signal, e.g. by using frequency selective- or frequency sensitive elements
    • H04L27/152—Demodulator circuits; Receiver circuits with demodulation using spectral properties of the received signal, e.g. by using frequency selective- or frequency sensitive elements using controlled oscillators, e.g. PLL arrangements
    • H04L27/1525—Demodulator circuits; Receiver circuits with demodulation using spectral properties of the received signal, e.g. by using frequency selective- or frequency sensitive elements using controlled oscillators, e.g. PLL arrangements using quadrature demodulation
    • 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
    • H03D3/02—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/02—Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation
    • H04L27/06—Demodulator circuits; Receiver circuits
    • 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
    • H04L27/20—Modulator circuits; Transmitter circuits
    • H04L27/2003—Modulator circuits; Transmitter circuits for continuous phase modulation
    • H04L27/2007—Modulator circuits; Transmitter circuits for continuous phase modulation in which the phase change within each symbol period is constrained
    • H04L27/2014—Modulator circuits; Transmitter circuits for continuous phase modulation in which the phase change within each symbol period is constrained in which the phase changes in a piecewise linear manner during each symbol period, e.g. minimum shift keying, fast frequency shift keying
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Power Engineering (AREA)
  • Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
  • Burglar Alarm Systems (AREA)

Abstract

1,172,975. Demodulators. PLESSEY CO. Ltd. 23 Nov., 1966 [23 Nov., 1965], No.8435/69. Divided out of 1,172,974. Headings H3A and H3Q. A quadrature demodulator comprises: means 40, 41 for multiplying a received modulated signal with quadrature carrier frequency signals from source 42; means 44, 45 for filtering the outputs from the two multipliers; means 48 for squaring one of the two filtered signals; means 50 for sampling the other filtered signal at transition points in the sampled signal; a bistable circuit 51 arranged so that its state is determined by the sign of the previous sample; and means 52 for multiplying the squared signal by the output from the bi-stable circuit. The frequency of the source 42 is controlled by a signal derived from the filtered product of the outputs from filters 44, 45 by means of multiplier 46 and filter 47. The circuit may be used in conjunction with a modulator of the type described in Specification 1,172,976.
GB843569A 1965-11-23 1965-11-23 Improvements in or relating to Demodulation Systems Expired GB1172975A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB843569A GB1172975A (en) 1965-11-23 1965-11-23 Improvements in or relating to Demodulation Systems

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB843569A GB1172975A (en) 1965-11-23 1965-11-23 Improvements in or relating to Demodulation Systems
GB49825/65A GB1172974A (en) 1965-11-23 1965-11-23 Improvements in or relating to Modulation Systems

Publications (1)

Publication Number Publication Date
GB1172975A true GB1172975A (en) 1969-12-03

Family

ID=26242168

Family Applications (1)

Application Number Title Priority Date Filing Date
GB843569A Expired GB1172975A (en) 1965-11-23 1965-11-23 Improvements in or relating to Demodulation Systems

Country Status (1)

Country Link
GB (1) GB1172975A (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2711476A1 (en) * 1976-03-16 1977-09-22 Plessey Handel Investment Ag DUPLEX TRANSMITTER / RECEIVER DEVICE WORKING IN A COMMON CHANNEL
GB2000401A (en) * 1977-06-17 1979-01-04 Sony Corp Signal level detecting circuits automatic gain control circuits automatic colour control circuits for colour television receivers and colour television receivers
US4349919A (en) 1979-07-06 1982-09-14 Plessey Handel Und Investments Ag Transmitter/receivers capable of contemporaneous transmission/reception
WO1986003643A1 (en) * 1984-12-07 1986-06-19 Gesellschaft Zur Förderung Der Industrieorientiert Method and circuit for detecting the information contained in a received signal
EP0147120A3 (en) * 1983-12-12 1987-04-22 International Standard Electric Corporation A zero if demodulator and method of demodulation
GB2300318A (en) * 1981-02-10 1996-10-30 Plessey Co Ltd Improvements in or relating to transceivers
GB2380641A (en) * 2001-09-14 2003-04-09 Roke Manor Research common channel transceiver, which can reduce the noise from the transmitter antenna, appearing on the receiver antenna by using a digital filtering stage

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2711476A1 (en) * 1976-03-16 1977-09-22 Plessey Handel Investment Ag DUPLEX TRANSMITTER / RECEIVER DEVICE WORKING IN A COMMON CHANNEL
GB2000401A (en) * 1977-06-17 1979-01-04 Sony Corp Signal level detecting circuits automatic gain control circuits automatic colour control circuits for colour television receivers and colour television receivers
GB2000401B (en) * 1977-06-17 1982-02-03 Sony Corp Signal level detecting circuits automatic gain control circuits automatic colour control circuits for colour television receivers and colour television receivers
US4349919A (en) 1979-07-06 1982-09-14 Plessey Handel Und Investments Ag Transmitter/receivers capable of contemporaneous transmission/reception
GB2300318A (en) * 1981-02-10 1996-10-30 Plessey Co Ltd Improvements in or relating to transceivers
GB2300318B (en) * 1981-02-10 1997-03-19 Plessey Co Ltd Improvements in or relating to transceivers
EP0147120A3 (en) * 1983-12-12 1987-04-22 International Standard Electric Corporation A zero if demodulator and method of demodulation
WO1986003643A1 (en) * 1984-12-07 1986-06-19 Gesellschaft Zur Förderung Der Industrieorientiert Method and circuit for detecting the information contained in a received signal
US4745627A (en) * 1984-12-07 1988-05-17 Gesellschaft Zur Forderung Der Industrieorientierten Forschung An Den Schweizerischen Hochschulen Und Weiteren Institutionen Procedure and circuit for detection of the information of a received signal
GB2380641A (en) * 2001-09-14 2003-04-09 Roke Manor Research common channel transceiver, which can reduce the noise from the transmitter antenna, appearing on the receiver antenna by using a digital filtering stage
GB2380641B (en) * 2001-09-14 2004-03-24 Roke Manor Research Transceiver

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Legal Events

Date Code Title Description
PS Patent sealed
PLNP Patent lapsed through nonpayment of renewal fees