5.5. Summary
131
topics that make use of many of the techniques discussed in the current and previous
chapters.
Infobox 5.3 Speech coding standards based around CELP and RPE
There is an entire spectrum of speech coding and compression systems, and then another entire
spectrum designed to handle music and general audio. The tendency is for the higher rate algorithms
to have higher perceived quality – but there are also significant differentiating factors in the
computational complexity, and in the underlying techniques used: the class of CELP-based systems
contains many weird and wonderful performance-enhancing ideas in addition to the basic codebook
excited linear prediction structure.
Name
Description
G.723.1
The basic ITU CELP standard at 5.3 or 6.3 kbits/s
G.728
Low delay CELP, 16 kbits/s sampled at 8 kHz
G.729
Algebraic CELP 8 kbits/s standard
TETRA
CELP 4.8 kbits/s
FS1015
LPC-based tenth-order system at 2.4 kbits/s
FS1016
Basic CELP at 4.8 or 7.2 kbits/s
GSM 06.10
Regular pulse excited, 13.6 kbits/s
MELP
Mixed excitation CELP 1.6 to 2.4 kbits/s
QCELP
Basic CELP at 8 and 13 kbits/s
Many variants and extensions exist to these original standards.
132
Speech communications
Bibliography
• Principles of Computer Speech
I. H. Witten (Academic Press, 1982)
• Linear Prediction of Speech
J. Markel and A. Gray (Springer-Verlag, 1976)
• Advances in Speech, Hearing and Language Processing
Ed. W. A. Ainsworth (JAI Press, 1990)
• Spoken Language Processing: A Guide to Theory, Algorithm and System Develop-
ment
X. Huang (Prentice-Hall, 2001)
• Speech and Audio Signal Processing: Processing and Perception of Speech and
Music
B. Gold and N. Morgan (Wiley, 1999)
• Fundamentals of Speech Signal Processing
S. Saito and K. Nakata (Academic Press, 1985)
• Digital Processing of Speech Signals
L. R. Rabiner and R. W. Schafer (Prentice-Hall, 1978)
• Computer Speech Processing
F. Fallside and W. Woods (Prentice-Hall, 1985)
• The Acoustics of Speech Communication: Fundamentals, Speech Perception Theory,
and Technology
J. M. Pickett (Allyn and Bacon, 1998)
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