WO1995012922A3 - Procede et appareil de brouillage et de desembrouillage economiques de signaux basse frequence - Google Patents

Procede et appareil de brouillage et de desembrouillage economiques de signaux basse frequence Download PDF

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Publication number
WO1995012922A3
WO1995012922A3 PCT/US1994/011891 US9411891W WO9512922A3 WO 1995012922 A3 WO1995012922 A3 WO 1995012922A3 US 9411891 W US9411891 W US 9411891W WO 9512922 A3 WO9512922 A3 WO 9512922A3
Authority
WO
WIPO (PCT)
Prior art keywords
signal
carrier
modulators
scrambled
audio
Prior art date
Application number
PCT/US1994/011891
Other languages
English (en)
Other versions
WO1995012922A2 (fr
Inventor
Ronald Quan
Original Assignee
Macrovision Corp
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 to DK94931915T priority Critical patent/DK0744105T3/da
Priority to KR1019960703240A priority patent/KR100249656B1/ko
Priority to NZ275269A priority patent/NZ275269A/en
Priority to EP94931915A priority patent/EP0744105B1/fr
Priority to DE69415555T priority patent/DE69415555T2/de
Priority to JP51324395A priority patent/JP3150700B2/ja
Application filed by Macrovision Corp filed Critical Macrovision Corp
Priority to CA002181691A priority patent/CA2181691C/fr
Priority to AU80828/94A priority patent/AU695981B2/en
Priority to AT94931915T priority patent/ATE175063T1/de
Publication of WO1995012922A2 publication Critical patent/WO1995012922A2/fr
Publication of WO1995012922A3 publication Critical patent/WO1995012922A3/fr
Priority to HK98114981A priority patent/HK1013747A1/xx

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)
  • Amplitude Modulation (AREA)
  • Transmission Systems Not Characterized By The Medium Used For Transmission (AREA)
  • Signal Processing For Digital Recording And Reproducing (AREA)
  • Reverberation, Karaoke And Other Acoustics (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Transmitters (AREA)
  • Stereo-Broadcasting Methods (AREA)

Abstract

On désembrouille des signaux basse fréquence par modulation à double bande latérale du signal basse fréquence brouillé avec une porteuse de modulation dont la fréquence porteuse est légèrement supérieure au signal basse fréquence le plus élevé présent dans le signal basse fréquence brouillé. On produit ainsi un signal à double bande latérale qui est envoyé dans un filtre passe-bas qui est à son tour modulé par une deuxième fréquence porteuse qui est inférieure au signal de la première porteuse, au moyen d'une valeur égale au spectre décalé du signal brouillé de départ. Le premier filtre passe-bas élimine toute porteuse résiduelle en provenance du premier modulateur qui résulte de l'intermodulation des deux fréquences de modulation qui devraient être audibles à sa sortie du désembrouilleur. Les modulateurs utilisés sont des modulateurs du type à commutateur à faible bruit qui améliorent le rapport signal/bruit dans le signal désembrouillé par rapport aux modulateurs linéaires utilisés jusqu'à aujourd'hui. Le fait d'utiliser des modulateurs du type à commutateur permet de produire un dispositif moins coûteux et plus performant. Un dispositif de brouillage associé utilise des techniques similaires pour assurer une meilleure performance à coût inférieur.
PCT/US1994/011891 1993-10-26 1994-10-18 Procede et appareil de brouillage et de desembrouillage economiques de signaux basse frequence WO1995012922A2 (fr)

Priority Applications (10)

Application Number Priority Date Filing Date Title
KR1019960703240A KR100249656B1 (ko) 1993-10-26 1994-10-18 저비용의 오디오 스크램블링과 디스크램블링 방법 및 장치(method and apparatus for low cost audio scramvling and descrambling)
NZ275269A NZ275269A (en) 1993-10-26 1994-10-18 Audio signal scrambling/descrambling, scrambled audio mixed with two fixed frequency signals
EP94931915A EP0744105B1 (fr) 1993-10-26 1994-10-18 Procede et systeme de brouillage et de desembrouillage d'un signal acoustique
DE69415555T DE69415555T2 (de) 1993-10-26 1994-10-18 Verfahren und einrichtung zur ver- und entschlüsselung von audiosignalen
JP51324395A JP3150700B2 (ja) 1993-10-26 1994-10-18 低コストのオーディオスクランブル及びデスクランブル方法及び装置
DK94931915T DK0744105T3 (da) 1993-10-26 1994-10-18 Fremgangsmåde og apparat til audiomaskering og -afmaskering med lave omkostninger
CA002181691A CA2181691C (fr) 1993-10-26 1994-10-18 Methode et appareil d'embrouillage et de desembrouillage de signaux audio
AU80828/94A AU695981B2 (en) 1993-10-26 1994-10-18 Method and apparatus for low cost audio scrambling and descrambling
AT94931915T ATE175063T1 (de) 1993-10-26 1994-10-18 Verfahren und einrichtung zur ver- und entschlüsselung von audiosignalen
HK98114981A HK1013747A1 (en) 1993-10-26 1998-12-23 Method and system for audio scrambling and descrambling

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US14506693A 1993-10-26 1993-10-26
US08/145066 1993-10-26

Publications (2)

Publication Number Publication Date
WO1995012922A2 WO1995012922A2 (fr) 1995-05-11
WO1995012922A3 true WO1995012922A3 (fr) 1995-07-13

Family

ID=22511456

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1994/011891 WO1995012922A2 (fr) 1993-10-26 1994-10-18 Procede et appareil de brouillage et de desembrouillage economiques de signaux basse frequence

Country Status (14)

Country Link
EP (1) EP0744105B1 (fr)
JP (1) JP3150700B2 (fr)
KR (1) KR100249656B1 (fr)
AT (1) ATE175063T1 (fr)
AU (1) AU695981B2 (fr)
CA (1) CA2181691C (fr)
DE (1) DE69415555T2 (fr)
DK (1) DK0744105T3 (fr)
ES (1) ES2125494T3 (fr)
HK (1) HK1013747A1 (fr)
MY (1) MY111488A (fr)
NZ (1) NZ275269A (fr)
TW (1) TW311307B (fr)
WO (1) WO1995012922A2 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4636853A (en) * 1983-12-21 1987-01-13 Zenith Electronics Corporation Dynamic audio scrambling system
US5058159A (en) * 1989-06-15 1991-10-15 Macrovision Corporation Method and system for scrambling and descrambling audio information signals
US5159631A (en) * 1990-04-26 1992-10-27 Macrovision Corporation Audio scrambling system using in-band carrier

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4636853A (en) * 1983-12-21 1987-01-13 Zenith Electronics Corporation Dynamic audio scrambling system
US5058159A (en) * 1989-06-15 1991-10-15 Macrovision Corporation Method and system for scrambling and descrambling audio information signals
US5159631A (en) * 1990-04-26 1992-10-27 Macrovision Corporation Audio scrambling system using in-band carrier

Also Published As

Publication number Publication date
EP0744105B1 (fr) 1998-12-23
DE69415555T2 (de) 1999-05-12
AU8082894A (en) 1995-05-23
WO1995012922A2 (fr) 1995-05-11
HK1013747A1 (en) 1999-09-03
JP3150700B2 (ja) 2001-03-26
EP0744105A1 (fr) 1996-11-27
DE69415555D1 (de) 1999-02-04
CA2181691C (fr) 2000-10-17
JPH10500259A (ja) 1998-01-06
MY111488A (en) 2000-06-30
KR100249656B1 (ko) 2000-03-15
ATE175063T1 (de) 1999-01-15
CA2181691A1 (fr) 1995-05-11
TW311307B (fr) 1997-07-21
ES2125494T3 (es) 1999-03-01
AU695981B2 (en) 1998-08-27
NZ275269A (en) 1998-08-26
DK0744105T3 (da) 1999-08-23

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