Multiband Vector Quantization Based on Inner Product for Wideband Speech Coding

Joon-Hyuk CHANG  Sanjit K. MITRA  

IEICE TRANSACTIONS on Information and Systems   Vol.E88-D   No.11   pp.2606-2608
Publication Date: 2005/11/01
Online ISSN: 
DOI: 10.1093/ietisy/e88-d.11.2606
Print ISSN: 0916-8532
Type of Manuscript: LETTER
Category: Speech and Hearing
wideband speech coding,  VQ,  CELP,  MLT,  inner product,  

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This paper describes a multiband vector quantization (VQ) technique based on inner product for wideband speech coding at 16 kb/s. Our approach consists of splitting the input speech into two separate bands and then applying an independent coding scheme for each band. A code excited linear prediction (CELP) coder is used in the lower band while a transform based coding strategy is applied in the higher band. The spectral components in the higher frequency band are represented by a set of modulated lapped transform (MLT) coefficients. The higher frequency band is divided into three subbands, and the MLT coefficients construct a vector for each subband. Specifically, for the VQ of these vectors, an inner product-based distance measure is proposed as a new strategy. The proposed 16 kb/s coder with the inner-product based distortion measure achieves better performance than the 48 kb/s ITU-T G.722 in subjective quality tests.