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A high quality voice coder with integrated echo canceller and voice activity detector for mobile satellite applicationsIn the last decade, low bit rate speech coding research has received much attention resulting in newly developed, good quality, speech coders operating at as low as 4.8 Kb/s. Although speech quality at around 8 Kb/s is acceptable for a wide variety of applications, at 4.8 Kb/s more improvements in quality are necessary to make it acceptable to the majority of applications and users. In addition to the required low bit rate with acceptable speech quality, other facilities such as integrated digital echo cancellation and voice activity detection are now becoming necessary to provide a cost effective and compact solution. In this paper we describe a CELP speech coder with integrated echo canceller and a voice activity detector all of which have been implemented on a single DSP32C with 32 KBytes of SRAM. The quality of CELP coded speech has been improved significantly by a new codebook implementation which also simplifies the encoder/decoder complexity making room for the integration of a 64-tap echo canceller together with a voice activity detector.
Document ID
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Kondoz, A. M.
(Surrey Univ. Guildford, United Kingdom)
Evans, B. G.
(Surrey Univ. Guildford, United Kingdom)
Date Acquired
September 6, 2013
Publication Date
January 1, 1993
Publication Information
Publication: JPL, Proceedings of the Third International Mobile Satellite Conference (IMSC 1993)
Subject Category
Communications And Radar
Accession Number
Distribution Limits
Work of the US Gov. Public Use Permitted.
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