Increasing quality of CELP coders by source-filter interrelation using self organising maps

Author

Avkarogullari, Gokhan ; Ciloglu, Tolga

Author_Institution

R&D Dept., Havelsan Inc., Ankara, Turkey

fYear

1998

fDate

8-11 Sept. 1998

Firstpage

1

Lastpage

4

Abstract

There are various alternatives for secondary excitation formulation for CELP type speech coders. In this paper we present a secondary excitation codebook generation and search algorithm based on the information derived from the linear prediction filter. Source-filter interrelation is extracted using Kohonen Learning algorithm and filter parameters (LSFs) are clustered according to topographic neighbourhood. For each cluster a secondary excitation shape-gain codebook is generated. Using the class information that current LSFs belong, only the associated codebook is searched. Shape codebooks of size 128 and gain codebooks of size 32 lead to statistically indifferent synthetic voice quality according to listening test when compared to FS1016 CELP coder.

Keywords

filtering theory; linear codes; self-organising feature maps; speech codecs; speech coding; CELP type speech; FS1016 CELP coder; Kohonen learning algorithm; code excited linear predictive coder; filter parameters; linear prediction filter; search algorithm; secondary excitation codebook generation; secondary excitation formulation; self organising maps; shape-gain codebook; source-filter interrelation; synthetic voice quality; topographic neighbourhood; Bit rate; Filtering algorithms; Information filters; Speech; Speech coding; Training;

fLanguage

English

Publisher

ieee

Conference_Titel

Signal Processing Conference (EUSIPCO 1998), 9th European

Conference_Location

Rhodes

Print_ISBN

978-960-7620-06-4

Type

conf

Filename

7089877