BER Improvement Using Error Concealment  Technique for Pulse Code Modulation System

Ahmed Mohammed Ahmed

doi:10.24237/djes.2018.11110

Authors

Ahmed Mohammed Ahmed
hmed_zydi@yahoo.com
Department of Communication Engineering, Engineering College, University of Diyala, Iraq

Keywords:

PCM, Source Coding, Hard Decoding, Soft Decoding, and MAP estimation

Abstract

The output of pulse code modulation (PCM) encoder is statistically described; this description is used at the receiver to reduce the error of the received signal. Recently, PCM is the most important form of pulse modulation. Bit errors occur at the transmission of information through the communication system and the amount of error depends on the characteristics of the channel. In this paper, the voice message is sampled greater than Nyquist rate and quantized with scalar quantizer, then the quantized levels are encoded with resolution B bits assigned to each level. The binary data are mapped and transmitted over Gaussian noise channel. The system was designed without channel coding. At the receiver the statistical description is exploited to conceal the errors. The results show that a significant improvement gained in bit error rate that was reduced from 0.078 to 0.052 at 0 dB of Eb N0⁄ by soft decoding, compared to hard decoding.

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References

. Fingscheidt, Tim, and Peter Vary. Robust speech decoding: A universal approach to bit error concealment, Acoustics, Speech, and Signal Processing, 1997. ICASSP-97., 1997 IEEE International Conference on. Vol. 3. IEEE, 1997.

. Han, Sai, and Tim Fingscheidt. Variable-length versus fixed-length coding: On tradeoffs for soft-decision decoding. 2014 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP). IEEE, 2014.

. Pflug, Florian, and Tim Fingscheidt. "Robust ultra-low latency soft-decision decoding of linear PCM audio." IEEE Transactions on Audio, Speech, and Language Processing 21.11 (2013): 2324-2336.

Heinen, Stefan, Axel Geiler, and Peter Vary. "MAP channel decoding by exploiting multilevel source a priori knowledge." ITG FACHBERICHT (1998): 89-94.

Fingscheidt, Tim, and Peter Vary. Softbit speech decoding: A new approach to error concealment. IEEE Transactions on Speech and Audio Processing 9.3 (2001): 240-251.

Xiong. Fuqin. ARTECH HOUSE, INC. Digital Modulation Techniques. pp 4. Artech House.Boston. London, 2000.

J. Hagenauer, Viterbi decoding of convolutional codes for fadingand burst-channels, in Proc. 1980 Zurich Seminar Digital Commun., Zürich, Switzerland, 1980, pp. G2.1–G2.7. Hagenauer, Joachim. "Source-controlled channel decoding." IEEE Transactions on Communications 43.9 (1995), 2449-2457.

Farrell, Patrick Guy. Essentials of error-control coding. John Wiley & Sons, 2006.