High Speed Codebook Searching Algorithm for the CELP Vocoder in the Internet-Based Environment

  • So Yeon Min
  • Eun Sook Cho
  • Chul Jin Kim
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3981)


In general CELP type vocoders provide good speech quality around 4.8kbps. Among them, G.723.1 developed for Internet Phone and videoconferencing includes two vocoders, 5.3kbps ACELP and 6.3kbps MP-MLQ. Since 6.3kbps MP-MLQ requires large amount of computation for the fixed codebook search, it is difficult to realize real time processing for the internet-based environment. In order to improve the problem this paper proposes the new method that reduces the processing time up to about 30% of codebook search time. We first decide the grid bit, and then search the codebook. Grid bit is selected by comparison between the DC-removed original speech and synthesized speech, which is synthesized with only even or odd pulses of target vector.


Target Vector Pulse Position Speech Codec Experimental Result Computer Simulation Rate Communication System 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • So Yeon Min
    • 1
  • Eun Sook Cho
    • 2
  • Chul Jin Kim
    • 3
  1. 1.Dept. of Information & Telecommunication Eng.SeoulKorea
  2. 2.Dept. of Software Engr.Seoil CollegeSeoulKorea
  3. 3.Digital Solution CenterSamsung Electronics Co.SeoulKorea

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