US1886263A - Multiplex communication system - Google Patents

Multiplex communication system Download PDF

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Publication number
US1886263A
US1886263A US507065A US50706531A US1886263A US 1886263 A US1886263 A US 1886263A US 507065 A US507065 A US 507065A US 50706531 A US50706531 A US 50706531A US 1886263 A US1886263 A US 1886263A
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United States
Prior art keywords
transmitter
keying
frequencies
channels
multiplex
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Expired - Lifetime
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US507065A
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English (en)
Inventor
Ilberg Waldemar
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Telefunken AG
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Telefunken AG
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Publication date
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Publication of US1886263A publication Critical patent/US1886263A/en
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/08—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J9/00—Multiplex systems in which each channel is represented by a different type of modulation of the carrier
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/02—Channels characterised by the type of signal
    • H04L5/06—Channels characterised by the type of signal the signals being represented by different frequencies

Definitions

  • the present invention relates to a method of and means for radio multiplex telegraphy.
  • Radio communication channels comprising transmitter, and receiver as a general rule permit only of the simultaneous transmission of one message.
  • Radio communication channels comprising transmitter, and receiver as a general rule permit only of the simultaneous transmission of one message.
  • the prior art that, for the purpose of obtaining with a given radio equipment several simultaneous communication channels, recourse may be had to the scheme to modulate the radio frequency carrier wave with a correspondingly great number of tonal or superaudible frequencies, and to render these in turn to act as carriers for signal modulation.
  • the various ensuing communication channels are separated at the receiving end, for instance, by the aid of suitable filter circuits.
  • such a scheme involves the disadvantage that in such division into n many channels, each of the chan-- nels will share only of the aggregate transmitter energy, and the resultant efiiciency of the equipment is only low.
  • the principal object of the present invention is, therefore, a multiplex and especially a duplex telegraphy method which is free from the above mentioned disadvantage.
  • the underlying idea shall be described in what follows by means of two simultaneously operated channels, it being evident to the man trained in the art that the application of the basic principle of this invention to three or more channels is readily feasible; and each one of such channels is readily operable for code or picture telegraphy.
  • transmitter 1 space (2) transmitter 1 dash (3) transmitter 1 ace transmitter'2 dash (4) transmitter 1 ash transmitter 2 dash.
  • FIG. 1 A transmitter scheme working according to this principle is illustrated in Fig. 1 of the accompanying drawing, and a-suitable form of construction of a receiver equipment adapted to effect separation or filtering of the two communication channels is illustrated by Fig; 2, where Fig. 2a indicates conventionally a receiver, and Figs. '26 and 20 indicate the range of the filters cooperating with the receiver.
  • Waves or frequencies e0 w and w are produced by the three generators1 ,2 and 3. respectively, which may be any well known type of thermionic tube generators, for example, and these generated frequencies are fed to the modulating means 4 of the'radio frequency transmitter 5 by way of relays 1a, 2a and 3a coordinated thereto.
  • the audio frequency waves obtained by demodulation from the incoming radio frequency band are brought to act upon two selectively actingmeans such as filters 1 and-2 which are coordinated to the two communication channels. Suitable transmission ranges of these two filters are shown in diagrammatic man ner by Figs. 2b and 20. Connected to the output of the filters is the indicator means for the two channels.
  • the indicators may be telephone receivers, undulators, picture recorders, and the like.
  • a multiplex telegraphy system comprising a keying means for. each channel in the multiplex system
  • a multiplex telegraphy system comprising a keying means for each channel in the multiplex system, each having a marking and spacing position, a plurality of sources of different modulation frequencies corresponding in number to the possible combinations of simultaneous operating conditions of the keying means for the several channels, an energy transmitter, and
  • a multiplex telegraphy system comprising a keying means for each channel in the multiplex system, each of said keying means having a marking and spacing position, an energy transmitter, means coordinated with said keying means for separately modulating said energy transmitter by a. plurality of modulation frequencies corresponding in number to the possible combinations of simultaneous operating conditions of the keying means for the several channels, means for receiving the energy transmitted, means for restoring the several transmitted modulation frequencies at the receiver, and a plurality of signal indicating means coordinated to the various channels for indicating the keying positions of the several keys of the transmitter.
  • a multiplex telegraphy system compris-' ing a keying means for each channel in the multiplex system, each of said keying means having a marking and spacing position, an
  • energy transmitter a plurality of sources of tion frequencies tion,- a
  • modulating currents each of a different frequency and corresponding in number to the possible combinations of simultaneous operating conditions of the keying means for the several channels, means coordinated Withsaid keying means for modulating said energy transmitter by a single one of a plurality of sources of modulation frequencies for each separate position of said keying means, means or receiving the energy transmitted, means for restoring the several transmitted modulaat the receiver, and a plurality of signal indicating means coordinated to the various channels for indicating the keying positions of the several keys of the transmitter.
  • a pair of keying means for producing separate signal indications, each of said keying means having a marking and spacing position, a transmitter, a plurality of oscillation generators for generating frequencies of predetermined value, means for modulating said transmitter by a separate one of said generated frequencies for marking positions of both of said keying means or for spacing on one of said keying means and marking on the other, andmeans for interrupting the transmission for spacing on each of said keying means.
  • a receiving means for transmitted signals a pair of filters connected with the outplt of said receiving means, each of said filters having overlapping cut-ofi' points, a signal indicator connected with each 'of said filters, and means provided by said overlapping cut-ofi points on said filters to cause said indicators to operate separately or collectively in accordance with received signal impulses for simultaneously indicating a plurality of'received messages.
  • a plurality of keys for modulated by determining messages sent out from the transmitter a plurality of oscillation generators each of different frequency for modulating said transmitter, and means cooperating with the keys for modulating said. transmitter by a single one of said different frequencies for different possible combinations of spacing 122nd marking positions of said plurality of eys.
  • a transmitter for transmitting space and mark typeof messages, means for separately modulatingvthe transmitter at a plurality of different frequencies corresponding in number to the possible combinations of space and mark, key positions of the pair. of keying means, and means controlled by the position of said keying means for controlling the modulation frequency of said transmitter.
  • a method of multiplex communication comprising producing a plurality of messages each as a series of spacing and marking impulses, generating a plurality of modulation frequencies in excess of the number of mes sages simultaneously transmitted, limiting the effective modulation frequency to a single frequency at any instant in accordance with the combinations of spacing and marking positions of the various messages simultaneously transmitted, and transmitting a signal a separate one of the several modulation frequencies for each of the possible combinations of spacings and markings of each of the messages transmitted.
  • the method of determining and separating a plurality of simultaneously transmitted messages which comprises receiving j signals modulated at a plurality of different frequencies for the possible combinations of spacings and markings on each of the simultaneously transmitted messages, filtering the received signals to separate the several modulating frequencies, causing predetermined modulation frequencies to overlap in the filtering for predetermined conditions of marking and spacing on each of the channels, and producing indications of the spacing and marking positions on each of the message channelsin accordance with the filtered received signals.
  • a multiplex signalling system comprising signal producing means, a plurality of 0scillation generators each of different frequency, a transmitter, and means operative to connect a different one of said oscillation generators with said transmitter to modulate the transmitter at one of said generated frequencies for each combination of the presence or absence of signals on said signal producing means.
  • a multiplex signalling system comprlsing a pair of keying instrumentalities each having on and off positions for indicating the presence or absence of energizing impulses thereon, a signal transmitter, a plurality of oscillation generators each of difierent frequency, means to connect a single one of each of said oscillation generators with said transmitter so as to modulate the transmitter at one of said frequencies for each combination of on and off position of each of said keying instrumentalities, which combination includes an on position of at least one of said keying instrumentalities to change the modulation frequency on said transmitter, and means pcrative from the on position of each of saidplurality of keying instrumentalities for in- 'cators,
  • a receiving system for transmitted signals modulated at each of aplurality of modulation frequencies comprising a signal receiving amplifier, a plurality of signal indiand a filter circuit tuned to pass two with each of said signal indicators so that by the overlapping cut-oil points of said filters said si al indicators operate individually or collectively to indicate simultaneously a-plurality of reoeivec%V messages.

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  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Multimedia (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Selective Calling Equipment (AREA)
  • Near-Field Transmission Systems (AREA)
  • Optical Communication System (AREA)
  • Facsimiles In General (AREA)
US507065A 1930-01-03 1931-01-07 Multiplex communication system Expired - Lifetime US1886263A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE540850T 1930-01-03

Publications (1)

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US1886263A true US1886263A (en) 1932-11-01

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US507065A Expired - Lifetime US1886263A (en) 1930-01-03 1931-01-07 Multiplex communication system

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US (1) US1886263A (de)
AT (1) AT127989B (de)
DE (2) DE540850C (de)
FR (1) FR708641A (de)
GB (2) GB359812A (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2464837A (en) * 1946-05-02 1949-03-22 Florian J Werthmann Radio teletype system
US2993958A (en) * 1956-10-17 1961-07-25 American Telephone & Telegraph Radiant energy receiving system
US3141066A (en) * 1956-11-08 1964-07-14 Itt Double side band, suppressed-carrier, phase shift type telegraph system
US4555791A (en) * 1981-05-19 1985-11-26 Jeumont-Schneider Corporation Method and apparatus for determination of the state of an all-or-none modulated alternating signal in a perturbed environment

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2538829A (en) * 1945-04-21 1951-01-23 Rca Corp Multiplex telegraph system using frequency discrimination

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2464837A (en) * 1946-05-02 1949-03-22 Florian J Werthmann Radio teletype system
US2993958A (en) * 1956-10-17 1961-07-25 American Telephone & Telegraph Radiant energy receiving system
US3141066A (en) * 1956-11-08 1964-07-14 Itt Double side band, suppressed-carrier, phase shift type telegraph system
US4555791A (en) * 1981-05-19 1985-11-26 Jeumont-Schneider Corporation Method and apparatus for determination of the state of an all-or-none modulated alternating signal in a perturbed environment

Also Published As

Publication number Publication date
GB359812A (en) 1931-10-29
DE528682C (de) 1932-11-15
GB355164A (en) 1931-08-20
FR708641A (fr) 1931-07-27
DE540850C (de) 1934-01-05
AT127989B (de) 1932-04-25

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