Global Patent Index - EP 1378887 A1

EP 1378887 A1 20040107 - Generation method of comfort noise frames (CNF)

Title (en)

Generation method of comfort noise frames (CNF)

Title (de)

Verfahren zur Erzeugung von Komfortgeräusch-Rahmen (CNF)

Title (fr)

Procédé de génération de trames bruit de confort (CNF)

Publication

EP 1378887 A1 20040107 (EN)

Application

EP 02380144 A 20020702

Priority

EP 02380144 A 20020702

Abstract (en)

A generation method of Comfort Noise Frames (CNF) in a TETRA system is described, for the generation of background noise frames in an emitter terminal, which must be transmitted during the periods of silence of said emitter terminal. The invention, also applicable to the case of the GSM standard, uses algorithmic alternatives for generating the frames by means of applying an algorithm to the parameters given by the control block terminal vocoder to the vocoder control block, the latter including a Vocal Activity Detector (VAD) and a comfort noise parameters calculation block. The method of the invention foresees the adaptation phases of the GSM standard VAD to that of TETRA, the CNF frame calculation, and the gains averaging by alternating the values of the quantizer, such that the average of the values over the subframes is as close as possible to the desired energy. <IMAGE>

IPC 1-7

G10L 19/00

IPC 8 full level

G10L 19/012 (2013.01); G10L 19/16 (2013.01)

CPC (source: EP)

G10L 19/012 (2013.01); G10L 19/173 (2013.01)

Citation (search report)

  • [A] EP 0843301 A2 19980520 - NOKIA MOBILE PHONES LTD [FI]
  • [DA] "Digital cellular telecomunications system (Phase2); Voice Activity Detector (VAD) for Enhanced Full Rate (EFR) speech traffic channels (GSM 06.82 version 4.0.1)", EN 301 249 V4.0.1, XX, XX, 1 December 1997 (1997-12-01), XX, pages 1 - 19, XP002224624
  • [A] "Terrestrial Trunked Radio (TETRA); Speech codec for full-rate traffic channel: Part 2: TETRA codec", ETS 300 395-2, XX, XX, 1 February 1998 (1998-02-01), XX, pages 1 - 92, XP002224625

Designated contracting state (EPC)

AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LI LU MC NL PT SE SK TR

DOCDB simple family (publication)

EP 1378887 A1 20040107; EP 1378887 B1 20060405; AT E322732 T1 20060415; DE 60210435 D1 20060518; ES 2261619 T3 20061116

DOCDB simple family (application)

EP 02380144 A 20020702; AT 02380144 T 20020702; DE 60210435 T 20020702; ES 02380144 T 20020702