Low Complexity Turbo Decoder with ACS Unit

  IJETT-book-cover  International Journal of Engineering Trends and Technology (IJETT)          
© 2016 by IJETT Journal
Volume-36 Number-8
Year of Publication : 2016
Authors : Liji Jose A, Sethu Raj


Liji Jose A, Sethu Raj"Low Complexity Turbo Decoder with ACS Unit", International Journal of Engineering Trends and Technology (IJETT), V36(8),446-451 June 2016. ISSN:2231-5381. www.ijettjournal.org. published by seventh sense research group

Since the turbo codes facilitate low transmission energy consumption, they have been recently considered for energy constrained wireless communication applications. This paper proposes low complexity turbo decoder architecture with ACS (Add Compare Select) unit. This paper shows the simulation of the energy efficient turbo encoder and decoder for the wireless sensor networks. Simulations were done by using the Model Sim. The turbo encoder is simulated using flip flops. Here two stage flip flop convolutional encoders were used for encoding. For the decoding purposes different MAP algorithms were employed. The better algorithm is determined by comparing the Constant Log MAP algorithm and LUT Log MAP algorithm. For analysing the two algorithms Quartus II were used. The decoder performs with α, β and γ. α and β were the node metrics and γ is the branch metrics. The iterations required for finding the metrics were performed in the ACS modules. The simulated results shows that Constant Log MAP algorithm is better on the basis of power consumption, but in the basis of error correction LUT Log MAP algorithm is more efficient.


[1] Patrick Robertson, Peter Hoeher, Emmanuelle Villebrun, ―Optimal and Sub-Optimal Maximum A Posteriori Algorithms Suitable for Turbo Decoding, European Transactions on Telecommunication, vol.8, pp-119-125, March 1997.
[2] W.J. Gross and P.G. Gulak, ―Simplified MAP Algorithm Suitable for Implementation of Turbo Decoders, IEEE Electronics Letter, 1998.
[3] Zhongfeng Wang, Xinming Huang, ―High-Speed VLSI Architectures for Turbo Decoders, IEEE Transaction on VLSI design.
[4] Zhongfeng Wang,Keshab K. Parhi, ―Area-Efficient High- Speed Decoding Schemes for Turbo Decoders, IEEE Transactions on VLSI, vol.10, no.6, pp:902-912,2002.
[5] Ibrahim Al-Mohandes and Mohamed Elmasry, ―A Low- Power 5 Mb/s Turbo Decoder for Third-Generation Wireless Terminals, IEEE Canadian Conference on Electrical and Computer Engineering, vol.4, pp:2387-2390, 2004.
[6] Santosh Shah and V. Sinha, ―Iterative Decoding vs. Viterbi Decoding: A Comparison, National Conference on Communications, IIT Bombay, p.494-497, February 2008.
[7] Pallavi Reddy, Fabein Clermidy Rasheed Al Khayat and Amer Baghdadi, ―Power Consumption Analysis and Energy Efficient Optimization for Turbo Decoder Implementation, IEEE Int Symposium On System On Chip, pp:12-17, 2010.
[8] Liang Li, Robert G. Maunder, Bashir M. Al-Hashimi, Mark Zwolinski, Lajos Hanzo, ―Energy-Conscious Turbo Decoder Design: A Joint Signal Processing and Transmit Energy Reduction Approach, IEEE Transactions on Vehicular Technology, vol.62, no.8, pp-3627-3638 Oct 2013.
[9] Mrs.K.M.Bogawar, Ms.Sharda Mungale Dr.Manish Chavan, ― Implementation of Turbo encoder and Decoder, International Journal of Engineering Trends and Technology (IJETT) – Volume 8 Number 2- Feb 2014.
[10] Liang Li, Robert G. Maunder, Bashir M. Al-Hashimi, Lajos Hanzo, ―A LowComplexity Turbo Decoder Architecture for Energy-Efficient Wireless Sensor Networks, IEEE Transactions On VLSI, vol.21, pp: 14-22, 2013.
[11] Varsha Ramesh, M.Thangamani, ― Adaptive Turbo Decoder with FSM based Interleaver Address Generator, International Journal of Engineering Trends and Technology (IJETT) – Volume 21 Number 3 – March 2015.
[12] Maurizio Martina, Stylianos Papaharalabos, P. Takis Mathiopoulos, Guido Masera, ―Simplified Log-MAP Algorithm for Very Low-Complexity Turbo Decoder Hardware Architectures, IEEE Transactions on Instrumentation and Measurement, vol. 63, no.3, pp:531- 537,Mar2014.

Wireless Sensor Networks, Energy Efficiency, Error correcting code, Log MAP algorithm, Turbo codes.