Joint source-channel (de-)coding for mobile communications

Real world source coding algorithms usually leave a certain amount of redundancy within the coded bit stream. Shannon (1948) already mentioned that this redundancy can be exploited at the receiver side to achieve a higher robustness against channel errors. We show how joint source-channel decoding can be performed in a way that is applicable to any mobile communication system standard. Considerable gains in terms of bit error rate or signal-to-noise ratio (SNR) are possible dependent on the amount of redundancy. However, an even better performance can be achieved by changing also the transmitter sided source and channel encoders. We propose an encoding concept employing low-dimensional quantization. Keeping the gross bit rate as well as the clean channel quality the same, it decreases the complexity of the source encoder and the decoder significantly. Finally, we give an application of our methods to spectral coefficient coding in speech transmission over a Rayleigh fading channel resulting in channel SNR gains of about 2 dB as compared to state-of-the-art (de-)coding and bad frame handling methods.

[1]  Tim Fingscheidt,et al.  Robust GSM speech decoding using the channel decoder's soft output , 1997, EUROSPEECH.

[2]  Joachim Hagenauer,et al.  A Viterbi algorithm with soft-decision outputs and its applications , 1989, IEEE Global Telecommunications Conference, 1989, and Exhibition. 'Communications Technology for the 1990s and Beyond.

[3]  N. Gortz,et al.  Joint source channel decoding using bit-reliability information and source statistics , 1998, Proceedings. 1998 IEEE International Symposium on Information Theory (Cat. No.98CH36252).

[4]  C.G. Gerlach.  A probabilistic framework for optimum speech extrapolation in digital mobile radio , 1993, 1993 IEEE International Conference on Acoustics, Speech, and Signal Processing.

[5]  Joel Max,et al.  Quantizing for minimum distortion , 1960, IRE Trans. Inf. Theory.

[6]  F. Itakura.  Line spectrum representation of linear predictor coefficients of speech signals , 1975 .

[7]  Robert M. Gray,et al.  The design of joint source and channel trellis waveform coders , 1987, IEEE Trans. Inf. Theory.

[8]  Fady Alajaji,et al.  Source-dependent channel coding of CELP speech over land mobile radio channels , 1995, Proceedings of MILCOM '95.

[9]  Nariman Farvardin,et al.  A study of vector quantization for noisy channels , 1990, IEEE Trans. Inf. Theory.

[10]  Paul K. M. Ho,et al.  Robust vector quantization for noisy channels using soft decision and sequential decoding , 1994, Eur. Trans. Telecommun..

[11]  P. Vary,et al.  Speech decoding with error concealment using residual source redundancy , 1997, 1997 IEEE Workshop on Speech Coding for Telecommunications Proceedings. Back to Basics: Attacking Fundamental Problems in Speech Coding.

[12]  John Cocke,et al.  Optimal decoding of linear codes for minimizing symbol error rate (Corresp.) , 1974, IEEE Trans. Inf. Theory.

[13]  Nam C. Phamdo,et al.  Optimal detection of discrete Markov sources over discrete memoryless channels - applications to combined source-channel coding , 1994, IEEE Trans. Inf. Theory.

[14]  T.E. Fuja,et al.  Channel codes that exploit the residual redundancy in CELP-encoded speech , 1996, IEEE Trans. Speech Audio Process..

[15]  Biing-Hwang Juang,et al.  Line spectrum pair (LSP) and speech data compression , 1984, ICASSP.

[16]  Joachim Hagenauer.  Source-controlled channel decoding , 1995, IEEE Trans. Commun..

[17]  Fady Alajaji,et al.  Unequal error protection and source-channel decoding of CELP speech , 2002 .

[18]  Robert M. Gray,et al.  An Algorithm for Vector Quantizer Design , 1980, IEEE Trans. Commun..

[19]  Khalid Sayood,et al.  Use of residual redundancy in the design of joint source/channel coders , 1991, IEEE Trans. Commun..

[20]  Robert M. Gray,et al.  Joint source and noisy channel trellis encoding , 1981, IEEE Trans. Inf. Theory.

[21]  Joachim Hagenauer,et al.  Rate-compatible punctured convolutional codes (RCPC codes) and their applications , 1988, IEEE Trans. Commun..

[22]  Peter Vary,et al.  Joint speech codec parameter and channel decoding of parameter individual block codes (PIBC) , 1999, 1999 IEEE Workshop on Speech Coding Proceedings. Model, Coders, and Error Criteria (Cat. No.99EX351).

[23]  A. Gray,et al.  Distance measures for speech processing , 1976 .

[24]  Nariman Farvardin,et al.  On the performance and complexity of channel-optimized vector quantizers , 1991, IEEE Trans. Inf. Theory.

[25]  Jonathan G. Fiscus,et al.  Darpa Timit Acoustic-Phonetic Continuous Speech Corpus CD-ROM {TIMIT} | NIST , 1993 .

[26]  Peter Vary,et al.  Robust speech decoding: a universal approach to bit error concealment , 1997, 1997 IEEE International Conference on Acoustics, Speech, and Signal Processing.

[27]  A. Ruscitto,et al.  Channel decoding using residual intra-frame correlation in a GSM system , 1997 .

[28]  Thomas Fuja,et al.  Robust transmission of MELP-compressed speech: an illustrative example of joint source-channel decoding , 2003, IEEE Trans. Commun..

[29]  Carl-Erik W. Sundberg,et al.  The performance of rate-compatible punctured convolutional codes for digital mobile radio , 1990, IEEE Trans. Commun..

[30]  Thomas E. Fuja,et al.  Optimized error correction of MELP speech parameters via maximum a posteriori (MAP) techniques , 1999, 1999 IEEE Workshop on Speech Coding Proceedings. Model, Coders, and Error Criteria (Cat. No.99EX351).

[31]  Mikael Skoglund,et al.  Hadamard-Based Soft Decoding for Vector Quantization Over Noisy Channels , 1999, IEEE Trans. Inf. Theory.

[32]  Peter Vary,et al.  Softbit speech decoding: a new approach to error concealment , 2001, IEEE Trans. Speech Audio Process..

[33]  Kuldip K. Paliwal,et al.  Efficient vector quantization of LPC parameters at 24 bits/frame , 1993, IEEE Trans. Speech Audio Process..

[34]  NARIMAN FARVARDIN,et al.  Optimal quantizer design for noisy channels: An approach to combined source - channel coding , 1987, IEEE Trans. Inf. Theory.

[35]  Keang-Po Ho,et al.  Soft-decoding vector quantizer using reliability information from turbo-codes , 1999, IEEE Commun. Lett..

[36]  Kuldip K. Paliwal,et al.  Speech Coding and Synthesis , 1995 .

[37]  C. E. SHANNON,et al.  A mathematical theory of communication , 1948, MOCO.

[38]  Jack K. Wolf,et al.  On linear unequal error protection codes , 1967, IEEE Trans. Inf. Theory.

[39]  Tim Fingscheidt,et al.  Combined source/channel (de-)coding: can a priori information be used twice? , 2000, 2000 IEEE International Conference on Communications. ICC 2000. Global Convergence Through Communications. Conference Record.