ijett-book-cover  International Journal of Engineering Trends and Technology (IJETT)          
© 2013 by IJETT Journal
Volume-4 Issue-6                      
Year of Publication : 2013
Authors : M. M. Jadhav , Ankit Pancholi , Dr. A. M. Sapkal


M. M. Jadhav , Ankit Pancholi , Dr. A. M. Sapkal. "A NALYSIS AND IMPLEMENTATION OF SOFT - DECISION DECODING ALGORITHM OF LDPC ". International Journal of Engineering Trends and Technology (IJETT). V4(6):2380-2384 Jun 2013. ISSN:2231-5381. published by seventh sense research group.


Low - density parity - check (LDPC) codes are freeware codes designed by Gallager in the year 1993 and used in most of the CDMA technology. An approach to study and analyze a mathematical model of belief propagation algorithm for decoding the encoding data stream with block size of 4096 using a binary symmetric channel to achieve good error probability of 10 - 6 is simulated with 60 iterations. Due to large si ze of the matrix, the conventional block encoding method could require a significant number of computations. The algorithm will be implemented using an hardware platform of TMS320C6713 DSP processor based on the VLIW architecture with clock rate of 225MHz, well suited for arithmetic & logical calculations. A simulat ed algorithm adopts i terative approach with a code rate of one half where decoder operates alternatively on the bit nodes and the check nodes to find the most likely codeword giv ing a good error performance between 10 - 4 and 10 - 5 that is acceptable for video streaming on the internet. The experimental results shows that the dynamic range in computations is quite large resulting in numerical stability and intensive multiplication in the algorithm poses a challenge for implementation.


[1] R. G. Gallager, “Low density parity check codes,” IEEE Trans. Inform. Theory, vol. IT - 8, pp. 21 – 28, Jan. 1962.
[2] Saeedi and Hamid ,” Performance of Belief Propagation for Decoding LDPC Codes in the Presence of Channel Estimation Error “. Communication IEEE transaction on Dept. of Syst. & Comput er . Eng., Carleton Univ., Ottawa, Ont. vol. IT - 55, pp. 83 – 87, Jan. 2 007 .
[3] TMS320C6000 Code Composer Studio Tutorial, SPRU301C, Texas Instruments, Dallas, TX, 2000.
[4] TMS320C6713 DSK Technical Reference, 506735 - 0001 Rev.A, May,2003.
[5] M.P.C. Fossorier, M. Mihaljevic, and H. Imai, “Reduced complexity iterative decodi ng of low - density parity check codes based on belief propagation, ” IEEE Trans. on Comm., vol. 47,no. 5, pp. 673 – 680, May. 1999.
[6] Introducing Low - Density Parity - Check Codes ” , by Sarah J. Johnson School of Electrical Engineering and Computer Science The University of Newcastle , Australia - 2007 .
[7] TMS 320C6713 - A Floating point digital signal processor Lab Manual, SPRS186L ? DECEMBER 2001 ? REVISED NOVEMBER 2005.

Bit error rate , Belief propagation decoding , C6713 and BSC channel.