A dispersed vector generator used for a speech encoder or a speech decoder includes a pulse vector provider that provides a pulse vector having a signed unit pulse on one element of a vector axis. A dispersion pattern determiner determines a dispersion pattern of a set of waveforms defined before a start of encoding or decoding. A dispersed vector generator convolutes the pulse vector and the determined dispersion pattern to generate a dispersed vector. A length of the waveforms is shorter than a length of a sub-frame.
CROSS-REFERENCE TO RELATED APPLICATION
The present application is a continuation application of pending U.S. patent application Ser. No. 11/281,386, filed on Nov. 18, 2005, which is a continuation application of U.S. patent application Ser. No. 10/133,735, filed Apr. 29, 2002, which issued as U.S. Pat. No. 7,024,356 on Apr. 4, 2006, which is a continuation of U.S. patent application Ser. No. 09/319,933, filed on Jun. 18, 1999, which issued as U.S. Pat. No. 6,415,254 on Jul. 2, 2002, which is the National Stage of International Application No. PCT/JP98/04777, filed Oct. 22, 1998, the content of which is expressly incorporated by reference herein in its entirety. The International Application was not published under PCT 21 (2) in English.
Priority Data
Oct 22, 1997 [JP] 9-289412 Oct 28, 1997 [JP] 9-295130 Mar 31, 1998 [JP] 10-85717
