Full metadata record
DC FieldValueLanguage
dc.contributorDepartment of Electronic Engineeringen_US
dc.creatorWong, Chi-keung Julian-
dc.identifier.urihttps://theses.lib.polyu.edu.hk/handle/200/5056-
dc.languageEnglishen_US
dc.publisherHong Kong Polytechnic University-
dc.rightsAll rights reserveden_US
dc.titleCoding of speech at 16 kbit/s using low-delay code excited linear prediction (LD-CELP)en_US
dcterms.abstractThis thesis presents herewith a Low-Delay Code-Excited Linear Prediction (LD-CELP) speech coder which has been standardized in 1992 as a CCITT G Series Recommendation for universal applications of speech coding at 16 kbit/s. Low-Delay CELP coder has a performance equivalent or better than G.721 (32 kbit/s ADPCM) and meets all the speech quality requirements set by CCITT Study Group XV. The objectives of this thesis are to simulate the Low-Delay CELP speech coder in high level language (Turbo C Language) and to evaluate the speech quality by using objective measures in time and frequency domains. The algorithms of conventional CELP and Low-Delay CELP coders and concepts related to Low-delay CELP (including perceptual weighting filter, synthesis filter, excitation gain adaptation, excitation VQ codebook and adaptive postfilter) are described. A model of burst-noise channel is used for simulation. The simulation model is operated on coded speech files to evaluate the effects of speakers, input level variations, burst noise and codeword corruptions. To access the speech quality, objective measures such as segmental signal-to-noise ratio for waveform distortion measure; and LPC cepstrum distance measure for frequency spectrum distortion measure are employed.en_US
dcterms.extent76 leaves : ill. ; 30 cmen_US
dcterms.isPartOfPolyU Electronic Thesesen_US
dcterms.issued1994en_US
dcterms.educationalLevelAll Masteren_US
dcterms.educationalLevelM.Sc.en_US
dcterms.LCSHSpeech processing systemsen_US
dcterms.LCSHCoding theoryen_US
dcterms.LCSHSignal processing -- Digital techniquesen_US
dcterms.LCSHHong Kong Polytechnic -- Dissertationsen_US
dcterms.accessRightsrestricted accessen_US

Files in This Item:
File Description SizeFormat 
b11669822.pdfFor All Users (off-campus access for PolyU Staff & Students only)2.49 MBAdobe PDFView/Open


Copyright Undertaking

As a bona fide Library user, I declare that:

  1. I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
  2. I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
  3. I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.

By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.

Show simple item record

Please use this identifier to cite or link to this item: https://theses.lib.polyu.edu.hk/handle/200/5056