[1] Ahmed J. Jameel**, You Xiaohu, Gao Xiqi,. Joint Source-Channel Decoding of EVRC Speech EncoderUsing Residual Redundancy* [J]. Journal of Southeast University (English Edition), 2002, 18 (2): 103-107. [doi:10.3969/j.issn.1003-7985.2002.02.001]

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Joint Source-Channel Decoding of EVRC Speech EncoderUsing Residual Redundancy^*()

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Journal of Southeast University (English Edition)[ISSN:1003-7985/CN:32-1325/N]

Volumn:

18

Issue:

2002 2

Page:

103-107

Research Field:

Information and Communication Engineering

Publishing date:

2002-06-30

Info

Title:

Joint Source-Channel Decoding of EVRC Speech EncoderUsing Residual Redundancy^*

Author(s):

Ahmed J. Jameel^**;  You Xiaohu;  Gao Xiqi

National Mobile Communications Research Laboratory, Southeast University, Nanjing 210096, China

Keywords:

residual redundancy;  convolutional codes;  turbo codes

PACS:

TN929.533

DOI:

10.3969/j.issn.1003-7985.2002.02.001

Abstract:

The enhanced variable rate codec(EVRC)is a standard for the “Speech Service Option 3 for Wideband Spread Spectrum Digital System, ” which has been employed in both IS-95 cellular systems and ANSI J-STC-008 PCS(personal communications systems). This paper concentrates on channel decoders that exploit the residual redundancy inherent in the enhanced variable rate codec bitstream. This residual redundancy is quantified by modeling the parameters as first order Markov chains and computing the entropy rate based on the relative frequencies of transitions. Moreover, this residual redundancy can be exploited by an appropriately “tuned” channel decoder to provide substantial coding gain when compared with the decoders that do not exploit it. Channel coding schemes include convolutional codes, and iteratively decoded parallel concatenated convolutional “turbo” codes.

References:

[1] Shannon C E. A mathematical theory of communication [J]. Bell System Technical Journal, 1948, 27:379-423.
[2] Phamdo N, Farvardin N. Optimal detection of discrete markov sources over discrete memoryless channels-applications to combined source-channel coding[J]. IEEE Transactions on Information Theory, 1994, 40(1):186-193.
[3] Hagenauer J. Source-controlled channel decoding[J]. IEEE Transactions on Communications, 1995, 43(9):2449-2457.
[4] Enhanced Variable Rate Codec. Speech Service Option 3 for Wideband Spread Spectrum Digital Systems[S]. IS-127, July 19, 1996.
[5] Alajaji F I, Phamdo N, Fuja T E. Channel codes that exploit the residual redundancy in CELP-Encoded speech[J]. IEEE Transactions on Speech and Audio Processing, 1996, 4(5):325-336.
[6] Ahmed J. Jameel. Joint source-channel decoding for mobile communications[D]. Nanjing: Department of Radio Engineering, Southeast University:in preparation.
[7] Shu Lin, Costello Daniel J. Error control coding: fundamentals and applications [M]. Prentice-Hall, 1983.
[8] Heegard C, Wicker S B. Turbo coding[M].Kluwer Academic Publisher, 1998.

Memo

Memo:

* The project supported by the National Natural Science Foundation of China(69725001).
** Born in 1963, male, graduate, Iraq.
*** The term “redundancy” usually has three connotations: (1) the source has memory but is uniformly distributed; (2) the

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