Optimized MAP turbo decoder

The very powerful turbo codes are a breakthrough in coding theory. The implementation of the iterative turbo decoder however hampers their incorporation in real systems. We tackle this problem by optimizing the decoder on two levels: the separate decoder modules and the global decoder system. Our module level optimizations greatly reduce the decoding delay and energy. The main contribution of this paper is situated at the system level, where we present an optimized architecture that uses a better interleaver organization. The combination of the optimizations on both levels results in a significant decoder power (factor 3), area (factor 2) and latency (factor 2) reduction.

[1]  P. M. Chau,et al.  Reconfigurable signal processor for channel coding and decoding in low SNR wireless communications , 1998, 1998 IEEE Workshop on Signal Processing Systems. SIPS 98. Design and Implementation (Cat. No.98TH8374).

[2]  Francky Catthoor,et al.  Custom Memory Management Methodology , 1998, Springer US.

[3]  Francky Catthoor,et al.  Custom Memory Management Methodology: Exploration of Memory Organisation for Embedded Multimedia System Design , 1998 .

[4]  Dariush Divsalar,et al.  Soft-output decoding algorithms for continuous decoding of parallel concatenated convolutional codes , 1996, Proceedings of ICC/SUPERCOMM '96 - International Conference on Communications.

[5]  Patrick Robertson,et al.  A comparison of optimal and sub-optimal MAP decoding algorithms operating in the log domain , 1995, Proceedings IEEE International Conference on Communications ICC '95.

[6]  Wayne E. Stark,et al.  VLSI design and implementation of low-complexity adaptive turbo-code encoder and decoder for wireless mobile communication applications , 1998, 1998 IEEE Workshop on Signal Processing Systems. SIPS 98. Design and Implementation (Cat. No.98TH8374).

[7]  Claude Berrou,et al.  An IC for turbo-codes encoding and decoding , 1995, Proceedings ISSCC '95 - International Solid-State Circuits Conference.

[8]  S. G. Wilson,et al.  Stream-oriented turbo codes , 1998, VTC '98. 48th IEEE Vehicular Technology Conference. Pathway to Global Wireless Revolution (Cat. No.98CH36151).

[9]  Francky Catthoor,et al.  Energy efficient data transfer and storage organization for a MAP turbo decoder module , 1999, Proceedings. 1999 International Symposium on Low Power Electronics and Design (Cat. No.99TH8477).

[10]  S. S. Pietrobon,et al.  Interleaver design for turbo codes , 1994 .

[11]  S. S. Pietrobon.  Implementation and performance of a serial MAP decoder for use in an iterative turbo decoder , 1995, Proceedings of 1995 IEEE International Symposium on Information Theory.

[12]  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.

[13]  Sergio Benedetto,et al.  A soft-input soft-output maximum a posteriori (MAP) module to decode parallel and serial concatenated codes , 1996 .