DocumentCode :
589873
Title :
Implementation and evaluation of variable bit rates CELP coder
Author :
Mahmoud, E.M. ; Elgarf, Talaat A. ; Elhafez, Ahmed Abd ; Zekry, Abd El-halim
Author_Institution :
Commun. Eng. Dept., Modern Acad. of Eng. & Technol., Cairo, Egypt
fYear :
2012
fDate :
27-29 Nov. 2012
Firstpage :
75
Lastpage :
80
Abstract :
Speech communication has a central position in human communication. In wireless telephony communication, the goal of speech coding is to represent speech with the possible least number of bits while maintaining an acceptable level of quality. The lower the bit rates the increase of the number of users within the restricted bandwidth. This paper introduces an efficient method of reducing the amount of bits required to transmit with optimum speech quality. According to speech quality of received signal depending on channel condition, a variable bit rate speech coder is implemented to maintain the reasonable speech quality in various channel conditions. Various modes of bit rates are used in the implemented coder. Low bit rate modes are used in a bad channel condition to allow more bits for channel coding, while high bit rate is used in better channel conditions. The speech quality, in terms of variable bit rates, is measured using analytical evaluation.
Keywords :
channel coding; radiotelephony; speech coding; wireless channels; channel coding; channel condition; human communication; low bit rate modes; optimum speech quality; speech coding; speech communication; variable bit rate CELP coder; variable bit rate speech coder; wireless telephony communication; Bit rate; Codecs; Power harmonic filters; Signal to noise ratio; Speech; Speech coding; Vectors; CELP; G723.1; variable bit rate and speech quality;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Computer Engineering & Systems (ICCES), 2012 Seventh International Conference on
Conference_Location :
Cairo
Print_ISBN :
978-1-4673-2960-6
Type :
conf
DOI :
10.1109/ICCES.2012.6408487
Filename :
6408487
Link To Document :
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