EP 0729678 A1 19960904 - PROCESS AND DEVICE FOR SPEECH SCRAMBLING AND UNSCRAMBLING IN SPEECH TRANSMISSION
Title (en)
PROCESS AND DEVICE FOR SPEECH SCRAMBLING AND UNSCRAMBLING IN SPEECH TRANSMISSION
Title (de)
VERFAHREN UND EINRICHTUNG ZUR SPRACHVERSCHLEIERUNG UND -ENTSCHLEIERUNG BEI DER SPRACHÜBERTRAGUNG
Title (fr)
PROCEDE ET DISPOSITIF DE BROUILLAGE ET DE DESEMBROUILLAGE DE LA PAROLE LORS DE LA TRANSMISSION DE LA VOIX
Publication
Application
Priority
- DE 4339464 A 19931119
- EP 9403693 W 19941109
Abstract (en)
[origin: US5778073A] PCT No. PCT/EP94/03693 Sec. 371 Date May 14, 1996 Sec. 102(e) Date May 14, 1996 PCT Filed Nov. 9, 1994 PCT Pub. No. WO95/15627 PCT Pub. Date Jun. 8, 1995A digitized real voice signal is converted via complex filtering into a complex signal that is subjected to sampling rate reduction, the bandwidth of the respective complex filter corresponding to the sampling rate. The complex signal is phase-modulated by means of a code signal generated by a random-number generator and additively combined with a pilot signal (likewise phase-modulated in a random distribution) to form an encrypted useful signal for transmission. The useful signal is sequentially transmitted together with a preamble for synchronization and signal equalization at the receiver end. At the receiver end, clock synchronization is forced for a phase-modulated pilot signal produced at the receiver end and equalizer coefficients for an equalizer at the receiver end are calculated from the digitized received signal after complex filtering and corresponding sampling rate reduction, during a preamble recognition phase, at which point the phase of the useful signal decryption is initialized. The encrypted, transmitted signal is separated from its phase-modulated pilot signal, which is superimposed at the transmitter end, by linking to the synchronized pilot signal, which is produced at the receiver end, and the phase-modulated, encrypted digital speech signal thus obtained is subsequently decomposed by the code signal produced at the receiving end and clockcontrolled by the preamble.
IPC 1-7
IPC 8 full level
CPC (source: EP KR US)
H04K 1/00 (2013.01 - EP KR US); H04K 1/006 (2013.01 - EP US)
Citation (search report)
See references of WO 9515627A1
Designated contracting state (EPC)
AT BE CH DE DK ES FR GB GR IT LI LU NL SE
DOCDB simple family (publication)
US 5778073 A 19980707; AT E169787 T1 19980815; AU 8141394 A 19950619; CZ 143896 A3 19961113; DE 4339464 A1 19950524; DE 4339464 C2 19951116; DE 59406692 D1 19980917; EP 0729678 A1 19960904; EP 0729678 B1 19980812; FI 962106 A0 19960517; FI 962106 A 19960517; HU 9601333 D0 19960729; HU T74262 A 19961128; JP H09501291 A 19970204; KR 960706244 A 19961108; PL 174895 B1 19980930; PL 314289 A1 19960902; RU 2118059 C1 19980820; SG 54159 A1 19981116; SK 63096 A3 19961106; TW 252241 B 19950721; WO 9515627 A1 19950608; ZA 949167 B 19950725
DOCDB simple family (application)
US 64808496 A 19960514; AT 95900687 T 19941109; AU 8141394 A 19941109; CZ 143896 A 19941109; DE 4339464 A 19931119; DE 59406692 T 19941109; EP 9403693 W 19941109; EP 95900687 A 19941109; FI 962106 A 19960517; HU 9601333 A 19941109; JP 51535495 A 19941109; KR 19960702086 A 19960423; PL 31428994 A 19941109; RU 96105712 A 19941109; SG 1996002874 A 19941109; SK 63096 A 19941109; TW 83109931 A 19941027; ZA 949167 A 19941118