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Real Time Implementation of CELP based AMR NB 06.90 Speech Coder on TMS320C6713 DSP Kit & Its Analytical Evaluation of Performance in Simulink

Ninad S. Bhatt, Yogeshwar P. Kosta


In today’s wireless communication system, one of the major challenges is to maintain good quality of recovered speech at receiver with unpredictable variations and behavior in channel conditions. Modeling of channel is always a difficult task and channel condition is a decisive factor for quality of speech being reproduced at receiver. Till date many techniques have been evolved to mitigate the effect of channel. GSM Adaptive Multi Rate (AMR) 06.90 is one of such technique which counteracts the deleterious effect of channel on speech signals. This technique employs variable bit rate that dynamically switches to specific modes of operation (switching bit rates – called modes of operation) depending upon the channel conditions. This paper yields development of AMR coder based on Code Excited Linear Prediction algorithm. By affecting some of the key parameters of CELP coder, variable bitrates of AMR coder can be achieved tuning to different channel conditions. An e-test bench using Simulink is created in order to implement AMR coder based on CELP algorithm, and the same studied and investigated through series of simulations. Subsequently Subjective (Mean Opinion Score) and Objective (Perceptual Evaluation of Speech Quality, Signal to Noise Ratio, Segmented SNR) analysis have been carried out on proposed algorithm to evaluate its performance for various bitrate modes. The obtained results clearly advocate significant improvement (for each Subjective and Objective analysis parameters) over [17] while implemented in Simulink. It also reveals the fact that speech quality improvement is evident with respect to increase in bitrate modes. In next phase real time implementation of proposed coder on TMS320C6713 DSP Kit using Simulink Real Time Workshop (RTW) and Code Composer Studio has been discussed. The goal of real time implementation of the proposed coder is to observe the feasibility of coding and decoding of the proposed coder on DSP TMS320C6713 kit.


CELP, Code Composer Studio, ETSI, GSM-AMR, Simulink, Speech Coding

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D. Malkovic, “Speech Coding Methods in Mobile Radio Communication Systems”, 17th International Conference on Applied Electromagnetics and Communications, oct- 2003, Croatia

M. Budagavi, “Speech Coding in Mobile Radio Communication”, Proceedings of IEEE, Vol. 86, No. 7, July 1998.

Jerry D. Gibson, “Speech Coding Methods, Standards and Applications”, IEEE Circuits and Systems Magazine, IEEE Fourth Quarter 2005.

L. Besacier, “GSM Speech Coding and Speaker Recognition”, University of Neuchatel, A.L.Breguet, Switzerland

Xiao Jianming, Li Xun, Wan Lei, “Software Simulation in GSM Environment of Federal Standard 1016 CELP Vocoder”, International Conference on Communication Technology, Oct. 22-24,1998, Beijing, China

Eko Pryadi, Kuniwati Gandi, Herman Kanalebe. “Speech Compression Using CELP Speech Coding Technique In GSM AMR”, IEEE Conference, 2008

Jie Yang, Sheng sheng Yu, Mian Zhao “The Implementation and Optimization Of AMR Speech Codec On Dsp” , 2007 International Symposium on Intelligent Signal Processing and Communication Systems

T.Lundberg Et. Al. “Adaptive Thresholds for AMR Codec Mode Selections”, IEEE Conference 2005

K.Jarvinen “Standardization Of the Adaptive Multi Rate Codec”, IEEE Conference 2000.

Yi Hu, Philipos C. Loizou “Evaluation of Objective Quality Measures for Speech Enhancement”, IEEE Transactions on Audio, Speech and Language processing, Vol. 16, No. 1, Jan. 2008.

A. Rix, J. Beerends, M. Hollier, and A. Hekstra, Perceptual evaluation of speech quality (PESQ)-A new method for speech quality assessment of telephone networks and codecs, in Proc. IEEE Int. Conf. Acoust., Speech, Signal Process., vol. 2,2000, pp. 749–752.

B. Grundlehner, J. Lecocq, R. Balan, and J. Rosca, Performance assessment method for speech enhancement systems,in Proc. 1st Annu. IEEE BENELUX/DSP Valley Signal Process. Symp.,2005.

ITU-T, Application guide for objective quality measurement based on Recommendations P.862, P.862.1 and P. 862.2, Rec. P. 862. 3, 2005.

N. Bhatt Et. Al.,2010, Implementation & Performance Analysis of CELP based GSM AMR Codec using MATLAB, IEEE Conference,CNC 2010, Calicut, India.

The NOIZEUS database (2009). Available:

Y. Hu and P. Loizou, Subjective comparison and evaluation of speech enhancement algorithms, Speech Commun., vol. 49, pp. 588–601, 2007.

N. Bhatt, Y. Kosta, Overall Performance evaluation of Adaptive Multi Rate 06.90 codec based on Code Excited Linear Prediction algorithm using MATLAB, IJST, Springer, on line published dated 11-01-12

R.C. de Lamare, A. Alcaim, Strategies to improve performance of very low bitrate speech coders and application to a variable rate 1.2 kbps codec, IEEE proceeding, Vision, Image and Signal Processing, 152 (1), 2005

M. Ahsan raza, P. Akhtar, Implementation of Voice Excited Linear Prediction coding (VELP) on TMS320C6711 DSP Kit, IEEE conference,2007.


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