Modeling and Simulation of a Turbo Encoder and Decoder for Wireless Communication Systems

This report presents information about modeling and implementation of turbo codes. Turbo coding is a very powerful error correction technique that has made a tremendous impact on channel coding in the last few years. It outperforms all previously known coding schemes by achieving near Shannon limit error correction using simple component codes and large interleavers. The iterative decoding mechanism, recursive systematic encoders and use of interleavers are the characteristic features of turbo codes. The use of turbo codes enhances the data transmission efficiency in digital communications systems. This technique can also be used to provide a robust error correction solution to combat channel fading. The entire turbo coding scheme consists of recursive systematic encoders,interleavers, puncturing and the decoder. This report gives a brief overview of the various components of the turbo coding scheme, analyzes the complexities of the most popular turbo decoding algorithms, describes a suitable model of computation and discusses the various implementation methods of the maximum a posteriori (MAP) algorithm.

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

[2]  D. Graupe,et al.  Punctured Convolutional Codes of Rate (n - 1)/n and Simplified Maximum Likelihood Decoding , 1979 .

[3]  E.A. Lee,et al.  Synchronous data flow , 1987, Proceedings of the IEEE.

[4]  Thomas M. Cover,et al.  Elements of Information Theory , 2005 .

[5]  A. Glavieux,et al.  Near Shannon limit error-correcting coding and decoding: Turbo-codes. 1 , 1993, Proceedings of ICC '93 - IEEE International Conference on Communications.

[6]  S. S. Pietrobon,et al.  A Simplification of the Modified Bahl Decoding Algorithm for Systematic Convolutional Codes , 1994 .

[7]  S. S. Pietrobon,et al.  Terminating the trellis of turbo-codes in the same state , 1995 .

[8]  D. Divsalar,et al.  Turbo codes for deep-space communications , 1995 .

[9]  Alain Glavieux,et al.  Reflections on the Prize Paper : "Near optimum error-correcting coding and decoding: turbo codes" , 1998 .

[10]  Sorin Adrian Barbulescu,et al.  ITERATIVE DECODING OF TURBO CODES AND OTHER CONCATENATED CODES , 1996 .

[11]  Joachim Hagenauer,et al.  Iterative decoding of binary block and convolutional codes , 1996, IEEE Trans. Inf. Theory.

[12]  Dariush Divsalar,et al.  Turbo codes: principles and applications , 1997 .

[13]  Patrick Robertson,et al.  Optimal and sub-optimal maximum a posteriori algorithms suitable for turbo decoding , 1997, Eur. Trans. Telecommun..

[14]  C. Edwards,et al.  NASA's Deep Space Telecommunications Roadmap , 1998 .

[15]  Steven S. Pietrobon.  Implementation and performance of a turbo/MAP decoder , 1998, Int. J. Satell. Commun. Netw..

[16]  Gerhard Fettweis,et al.  Comparison of different turbo decoder realizations for IMT-2000 , 1999, Seamless Interconnection for Universal Services. Global Telecommunications Conference. GLOBECOM'99. (Cat. No.99CH37042).

[17]  Stephen A. Edwards,et al.  Languages for Digital Embedded Systems , 2000 .

[18]  N. J. A. Sloane,et al.  Interleaver design for turbo codes , 2001, IEEE J. Sel. Areas Commun..

[19]  S. A. Barbulescu.  Sliding window and interleaver design , 2001 .