Login | Register

A modified low-bit-rate ACELP speech coder and its implementation


A modified low-bit-rate ACELP speech coder and its implementation

Zhou, Jian Guang (2003) A modified low-bit-rate ACELP speech coder and its implementation. Masters thesis, Concordia University.

[thumbnail of MQ91162.pdf]
Text (application/pdf)
MQ91162.pdf - Accepted Version


In modern communication systems, low-bit-rate speech coder is widely employed to increase the bandwidth efficiency of the network. The ITU-T G.729 is one such speech coder extensively used in packet voice communication systems. Since the reduction in the complexity has been a major issue in designing and implementing low-bit-rate speech coder, the focus of this research is on reducing the complexity of the existing G.729 standard. Based on the fact that the fixed codebook search accounts for much of the computation in the coding process, in this thesis, the existing codebook search algorithm of G.729A, a reduced complexity version of G.729, is modified and incorporated into this standard. The test results on a general PC indicate that the modified search scheme reduces the computation load by about 40% with only a slight degradation in the perceptual quality of the speech. In the second part of this project, the modified speech coder is implemented on the TMS320C5416 DSK DSP board. First, the implementation scheme is described and the initial results for both the G.729A and the modified coder are presented. Then, several optimization procedures are developed to effectively reduce the run-time of the algorithm. With the optimized implementation, the run-time of the speech coder is significantly reduced to meet the real time requirement to process a single frame within 10 ms. As for the savings on the computational load, the run-time of the modified fixed codebook search algorithm is about 30% smaller than that of the original search scheme used in G.729A.

Divisions:Concordia University > Gina Cody School of Engineering and Computer Science > Electrical and Computer Engineering
Item Type:Thesis (Masters)
Authors:Zhou, Jian Guang
Pagination:xi, 86 leaves : ill. ; 29 cm.
Institution:Concordia University
Degree Name:M.A. Sc.
Program:Dept. of Electrical and Computer Engineering
Thesis Supervisor(s):Swamy, M. N. S
Identification Number:TK 7882 S65Z46 2003
ID Code:2374
Deposited By: Concordia University Library
Deposited On:27 Aug 2009 17:27
Last Modified:13 Jul 2020 19:52
Related URLs:
All items in Spectrum are protected by copyright, with all rights reserved. The use of items is governed by Spectrum's terms of access.

Repository Staff Only: item control page

Downloads per month over past year

Research related to the current document (at the CORE website)
- Research related to the current document (at the CORE website)
Back to top Back to top