(19)
(11) EP 0 694 907 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
15.10.1997 Bulletin 1997/42

(43) Date of publication A2:
31.01.1996 Bulletin 1996/05

(21) Application number: 95111278.8

(22) Date of filing: 18.07.1995
(51) International Patent Classification (IPC)6: G10L 9/14
(84) Designated Contracting States:
DE FR GB

(30) Priority: 19.07.1994 JP 187903/94

(71) Applicant: NEC CORPORATION
Tokyo (JP)

(72) Inventors:
  • Funaki, Keiichi, c/o NEC Corporation
    Tokyo (JP)
  • Ozawa, Kazunori, c/o NEC Corporation
    Tokyo (JP)

(74) Representative: Glawe, Delfs, Moll & Partner 
Patentanwälte Postfach 26 01 62
D-80058 München
D-80058 München (DE)

   


(54) Speech coder


(57) A long-period prediction circuit (160), which is provided in this speech coder and outputs an optimum delay code of delay codes indicative of a pitch correlation of a speech signal, extracts delay codes by selecting a predetermined section of delay codes and/or while evenly or unevenly thinning out the delay codes, conducts preliminary selection of delay codes through closed-loop search of the extracted delay codes and determines an optimum delay code by executing closed-loop search with respect to the preliminarily selected delay codes.






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