[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*(
)
利用残留冗余量的联合信源信道解码 在EVRC语音解码器中的应用
)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*
- 利用残留冗余量的联合信源信道解码 在EVRC语音解码器中的应用
- Author(s):
- Ahmed J. Jameel**, You Xiaohu, Gao Xiqi
- National Mobile Communications Research Laboratory, Southeast University, Nanjing 210096, China
- 阿哈麦德尤肖虎高西奇
- 东南大学移动通信国家重点实验室, 南京 210096
- 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.
- 宽带扩频系统的语音服务采用增强型的可变比率编码器, 该标准已在IS-95和J-STC-008个人移动通信系统得到应用.本文致力于利用增强可变比率编码器中内在残留冗余信息的信道解码器.由于残留冗余信息可以用一阶马尔夫模型表示, 同时相关频率的变化可以用熵率来表示, 从而, 信道解码器可利用这种残留冗余量.仿真结果表明, 和没有利用这种信息量的解码器相比, 由于编码增益, 系统性能有明显改善, 其中, 信道编码采用了卷积码、Turbo码两种方式.
References:
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[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.
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[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