GB1512696A - Camouflaged transmission of signals - Google Patents

Camouflaged transmission of signals

Info

Publication number
GB1512696A
GB1512696A GB28486/75A GB2848675A GB1512696A GB 1512696 A GB1512696 A GB 1512696A GB 28486/75 A GB28486/75 A GB 28486/75A GB 2848675 A GB2848675 A GB 2848675A GB 1512696 A GB1512696 A GB 1512696A
Authority
GB
United Kingdom
Prior art keywords
interchange
july
determined
signal
signals
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
GB28486/75A
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.)
Siemens AG
Original Assignee
Siemens 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
Priority claimed from DE19742434877 external-priority patent/DE2434877C3/en
Application filed by Siemens AG filed Critical Siemens AG
Publication of GB1512696A publication Critical patent/GB1512696A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
    • H04K1/00—Secret communication
    • H04K1/04—Secret communication by frequency scrambling, i.e. by transposing or inverting parts of the frequency band or by inverting the whole band

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Compression, Expansion, Code Conversion, And Decoders (AREA)
  • Time-Division Multiplex Systems (AREA)
  • Television Systems (AREA)
  • Transmitters (AREA)

Abstract

1512696 Scrambling systems SIEMENS AG 7 July 1975 [19 July 1974] 28486/75 Heading H4R A (speech) signal is scrambled by interchanging sub-bands according to a sequence determined by a generator Z1 controlled by a pulse sequence in the form of a cyclic variation in pulse repetition frequency (derived by multiplexing at M frequencies divided in FT1-FT8 from a carrier generator TV whose output is fed via switched interchange pattern circuits UE to frequency shift the signal sub-bands) the duration of each interchange being determined at Z2 from the same pulse sequence as employed for the interchange.
GB28486/75A 1974-07-19 1975-07-07 Camouflaged transmission of signals Expired GB1512696A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19742434877 DE2434877C3 (en) 1974-07-19 Device for the disguised transmission of speech signals

Publications (1)

Publication Number Publication Date
GB1512696A true GB1512696A (en) 1978-06-01

Family

ID=5921046

Family Applications (1)

Application Number Title Priority Date Filing Date
GB28486/75A Expired GB1512696A (en) 1974-07-19 1975-07-07 Camouflaged transmission of signals

Country Status (16)

Country Link
JP (1) JPS5826706B2 (en)
AT (1) AT341003B (en)
AU (1) AU501260B2 (en)
BE (1) BE831528A (en)
CH (1) CH596716A5 (en)
DK (1) DK140914C (en)
FR (1) FR2285029A1 (en)
GB (1) GB1512696A (en)
IE (1) IE41265B1 (en)
IL (1) IL47692A (en)
IN (1) IN147050B (en)
IT (1) IT1039917B (en)
LU (1) LU73007A1 (en)
NL (1) NL169664C (en)
SE (1) SE410259B (en)
ZA (1) ZA754406B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2151886A (en) * 1983-12-21 1985-07-24 British Broadcasting Corp Conditional-access broadcast transmission
GB2156190A (en) * 1984-01-26 1985-10-02 Univ British Columbia Modem

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2761281B2 (en) * 1990-05-17 1998-06-04 富士通株式会社 Encrypted communication method for multi-carrier communication system

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1278172A (en) * 1960-10-28 1961-12-08 Cie Ind Des Telephones Electronic coding device for radio or telephone links
FR2129013A5 (en) * 1971-03-11 1972-10-27 Snecma
GB1465923A (en) * 1973-04-03 1977-03-02 Siemens Ag Camouflaged speech signal transmission systems

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2151886A (en) * 1983-12-21 1985-07-24 British Broadcasting Corp Conditional-access broadcast transmission
GB2156190A (en) * 1984-01-26 1985-10-02 Univ British Columbia Modem
AU572950B2 (en) * 1984-01-26 1988-05-19 University Of British Columbia, The Modem for power line signalling

Also Published As

Publication number Publication date
NL169664C (en) 1982-08-02
IE41265L (en) 1976-01-19
AT341003B (en) 1978-01-10
DK140914B (en) 1979-12-03
NL169664B (en) 1982-03-01
ATA526575A (en) 1977-05-15
DE2434877B2 (en) 1976-05-13
CH596716A5 (en) 1978-03-15
IL47692A (en) 1977-11-30
AU8290875A (en) 1977-01-13
FR2285029B1 (en) 1977-12-16
FR2285029A1 (en) 1976-04-09
SE7508246L (en) 1976-01-20
DE2434877A1 (en) 1976-01-29
DK328275A (en) 1976-01-20
SE410259B (en) 1979-10-01
LU73007A1 (en) 1976-07-01
AU501260B2 (en) 1979-06-14
DK140914C (en) 1980-05-12
IE41265B1 (en) 1979-11-21
NL7508643A (en) 1976-01-21
BE831528A (en) 1976-01-19
JPS5134603A (en) 1976-03-24
IT1039917B (en) 1979-12-10
IL47692A0 (en) 1975-12-31
IN147050B (en) 1979-10-27
JPS5826706B2 (en) 1983-06-04
ZA754406B (en) 1976-06-30

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee