US2214916A - Radio transmission arrangement - Google Patents

Radio transmission arrangement Download PDF

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Publication number
US2214916A
US2214916A US180116A US18011637A US2214916A US 2214916 A US2214916 A US 2214916A US 180116 A US180116 A US 180116A US 18011637 A US18011637 A US 18011637A US 2214916 A US2214916 A US 2214916A
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US
United States
Prior art keywords
frequency
carrier
band
radio transmission
transmission arrangement
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 - Lifetime
Application number
US180116A
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English (en)
Inventor
Wiessner Alfred
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.)
Alcatel Lucent Deutschland AG
C Lorenz AG
Original Assignee
Standard Elektrik Lorenz AG
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 Standard Elektrik Lorenz AG filed Critical Standard Elektrik Lorenz AG
Application granted granted Critical
Publication of US2214916A publication Critical patent/US2214916A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J1/00—Frequency-division multiplex systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
    • H04M11/06—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
    • H04M11/062—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors using different frequency bands for speech and other data

Definitions

  • the present invention relates to communication systems especially adapted for transmitting a plurality of different messages at ultra high frequencies.
  • the invention has for its object to secure reliable operation of this type of systems by using possibly simple means.
  • the average frequency range utilized in interconnections of the aforesaid type involves certain difficulties, which can be removed merely by long wave operation.
  • the inventive idea proposes a quite different solution for obviating occurring dfculties,
  • the ultrahigh carrier frequency is directly modulated with narrow-band message frequencies, e. g. telegraph signals, while being indirectly modulated with wide-band message frequencies, particularly the speech frequency band, by the agency of an in- 35 termediate carrier frequency which is subsequently suppressed.
  • narrow-band message frequencies e. g. telegraph signals
  • wide-band message frequencies particularly the speech frequency band
  • the agency of an in- 35 termediate carrier frequency which is subsequently suppressed.
  • This new arrangement involves following advantages over the above mentioned known systems, which employ one separate carrier for the modulation of each of the different communication channels. It would be desirable to suppress the intermediate carrier in order to reduce the width of the frequency band and to modulate the ultra-high carrier frequency with one of the side bands obtained due to the intermediate frequency 5 modulation, however, the suppression of the intermediate frequency carrier involves considerable difficulties in cases that tone-frequency telegraph channels are concerned, because there are no reliable means available for such suppression within this frequencyrange. On the other hand,
  • the carrier is directly modulated with the telegraph signals, while the messages which demand wider frequency bands are adapted to modulate an intermediate carrier frequency which is suppressed in any known manner, for instance, in a bridge circuit comprising dry rectiers in which the modulation is effected.
  • the ultra-high carrier frequency is then modulated with one side band only, preferably the lower.
  • the provision of an intermediate carrier at the receiving side is then necessary in order to modulate the ultra high frequency carrier.
  • Difficulties involved with respect to the telegraph channels are not set up in this case, since the adding of the carrier in cases that speech frequency band is concerned, for example, does not require such an accuracy. In other words, some allowance is permissible without introducing troubles to the transmission.
  • Fig. 1 diagrammatically illustrates the modulation frequency band arrangement
  • Fig. 2 illustrates a circuit arrangement in block diagram, schematically demonstrates the position of the different frequencies within the frequency spectrum.
  • the ultra high carrier frequency is designated fu generated in transmitter l
  • ft I, ft 2 and ft 3 indicate three telegraph channels from telegraph apparatus 2, 3 and 4, and fs the speech channel output from filter 5, the lower side band of which is transmitted only.
  • the not transmitted intermediate carrier frequency of the speech channel is labelled fe.
  • the broad band or speech signals fs are generated at 6, and are used to modulate the carrier frequency fz produced in generator 1, in modulator
  • the modulated intermediate carrier is then passed through suppressor 9 which suppresses the carrier frequency and a single side band is impressed on transmitter l through the single rside band lter 5.
  • An arrangement for simultaneously transmitting a plurality of messages at ultra high frequencies comprising means for generating an ultra high carrier frequency, means for producing a plurality of closely adjacentnarrow frequency band message wave trains for transmitting separate messages, said narrow frequency bands all being below a given frequency, means 55 quency, and means for modulating said ultra high carrier frequency with the side band frequency of said modulated intermediate carrier.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Radio Relay Systems (AREA)
  • Transmitters (AREA)
  • Mobile Radio Communication Systems (AREA)
US180116A 1936-12-22 1937-12-16 Radio transmission arrangement Expired - Lifetime US2214916A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEL91684D DE720474C (de) 1936-12-22 1936-12-22 Anordnung zum gleichzeitigen UEbertragen mehrerer Nachrichten mittels einer Traegerwelle

Publications (1)

Publication Number Publication Date
US2214916A true US2214916A (en) 1940-09-17

Family

ID=6544596

Family Applications (1)

Application Number Title Priority Date Filing Date
US180116A Expired - Lifetime US2214916A (en) 1936-12-22 1937-12-16 Radio transmission arrangement

Country Status (4)

Country Link
US (1) US2214916A (de)
DE (1) DE720474C (de)
FR (1) FR829118A (de)
GB (1) GB493674A (de)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE861884C (de) * 1950-08-19 1953-01-08 Max Grundig Stereophonisches UEbertragungssystem
BE511901A (de) * 1951-06-08

Also Published As

Publication number Publication date
GB493674A (en) 1938-10-12
DE720474C (de) 1942-05-07
FR829118A (fr) 1938-06-13

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