GB1191843A - Improvements in or relating to Data Transmission Apparatus - Google Patents

Improvements in or relating to Data Transmission Apparatus

Info

Publication number
GB1191843A
GB1191843A GB3066466A GB3066466A GB1191843A GB 1191843 A GB1191843 A GB 1191843A GB 3066466 A GB3066466 A GB 3066466A GB 3066466 A GB3066466 A GB 3066466A GB 1191843 A GB1191843 A GB 1191843A
Authority
GB
United Kingdom
Prior art keywords
signal
dibit
output
fed
outputs
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
GB3066466A
Inventor
John Frank Greenaway
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.)
Plessey Co Ltd
Original Assignee
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 Plessey Co Ltd filed Critical Plessey Co Ltd
Priority to GB3066466A priority Critical patent/GB1191843A/en
Publication of GB1191843A publication Critical patent/GB1191843A/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00Modulated-carrier systems
    • H04L27/18Phase-modulated carrier systems, i.e. using phase-shift keying
    • H04L27/20Modulator circuits; Transmitter circuits
    • H04L27/2032Modulator circuits; Transmitter circuits for discrete phase modulation, e.g. in which the phase of the carrier is modulated in a nominally instantaneous manner
    • H04L27/2092Modulator circuits; Transmitter circuits for discrete phase modulation, e.g. in which the phase of the carrier is modulated in a nominally instantaneous manner with digital generation of the modulated carrier (does not include the modulation of a digitally generated carrier)

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Synchronisation In Digital Transmission Systems (AREA)

Abstract

1,191,843. Digital transmission systems. PLESSEY CO. Ltd. 7 July, 1967 [7 July, 1966], No. 30664/66. Heading H4P. A demodulator for differential phase-shift signals comprises a unit including a delay line to which the received signal is fed, the output of the delay line being selectively fed back to its input to derive a signal delayed by a multiple of the delay line period. Transmitter.-Input binary data is converted to dibit form, the dibits controlling the phase of a two-stage counter, fed by squarewave carrier frequency clock pulses, by subtracting from the count the binary number represented by a dibit. The output from the second stage is a signal in which each dibit is represented by *1¢ cycles of a square-wave which has a phase, relative to the preceding 1¢cycles, indicative of the dibit. This signal is filtered and transmitted. Receiver.-The signal is filtered and limited, the limiter output passing to a comparator and also to a unit which samples the signal several times per cycle. The samples pass to a gated feed-back delay unit which has a basic delay of one-quarter of a carrier cycle. By repeated feed-back the samples are delayed by multiples of a quarter cycle, the delay providing three outputs equal to the limited input signal delayed by 1“, and¢ 1¥ carrier cycles. These signals pass to a comparator wherein each is compared with the limited (and undelayed) signal. The resulting three outputs are fed to respective units, each comprising a Miller integrator and a threshold unit, to develop respective outputs corresponding to the three dibit signals other than 00, these outputs passing to a circuit giving a serial output identical to the signal at the transmitter input. The sampling pulses are also passed to counter/divider which outputs a clock signal synchronized with the received data. The comparator provides a fourth output by comparison of the 1“ and 1¥ cycle delayed signals, the result passing to a fourth integrator and threshold unit. The threshold unit pulses at each dibit level transition, and at each such pulse a pulse is either inserted or removed from the sampling pulse train fed to the divider to control the phase of the counter output.
GB3066466A 1966-07-07 1966-07-07 Improvements in or relating to Data Transmission Apparatus Expired GB1191843A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB3066466A GB1191843A (en) 1966-07-07 1966-07-07 Improvements in or relating to Data Transmission Apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3066466A GB1191843A (en) 1966-07-07 1966-07-07 Improvements in or relating to Data Transmission Apparatus

Publications (1)

Publication Number Publication Date
GB1191843A true GB1191843A (en) 1970-05-13

Family

ID=10311195

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3066466A Expired GB1191843A (en) 1966-07-07 1966-07-07 Improvements in or relating to Data Transmission Apparatus

Country Status (1)

Country Link
GB (1) GB1191843A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2143722A1 (en) * 1971-07-01 1973-02-09 Sanders Associates Inc
NL7611896A (en) * 1975-10-29 1977-05-03 Western Electric Co MODULATOR FOR DIFFERENTIAL PHASE-CODED DIGITAL DATA.

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2143722A1 (en) * 1971-07-01 1973-02-09 Sanders Associates Inc
NL7611896A (en) * 1975-10-29 1977-05-03 Western Electric Co MODULATOR FOR DIFFERENTIAL PHASE-CODED DIGITAL DATA.
FR2330217A1 (en) * 1975-10-29 1977-05-27 Western Electric Co MODULATOR FOR THE TRANSMISSION OF DATA IN DIFFERENTIAL PHASE MODULATION

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Legal Events

Date Code Title Description
PS Patent sealed
PE20 Patent expired after termination of 20 years