Cover
Vol. 16 No. 1 (2025)

Published: February 16, 2025

Pages: 13-20

Research Paper

Performance Measure of Turbo Code Using LLR Histogram

Mohammed AlMahamdy 1
1Department of Electrical Engineering, College of Engineering, University of Anbar, Ramadi, Iraq
History
  • Received: October 28, 2024
  • Revised: January 14, 2025
  • Accepted: February 10, 2025
  • Available Online: February 16, 2025
DOI

https://doi.org/10.37649/aengs.2025.154788.1110

Abstract

Turbo codes have been deployed in many cutting-edge technologies because they can achieve very high coding gains. Turbo decoders deploy at least two Soft-Input-Soft-Out (SISO) decoders, which operate iteratively to incorporate their results to conclude the output. The soft outputs from the used constituent SISO decoders develop gradually along the iterations. This development is studied and analyzed in this work to understand the dynamics leading to the results. Histograms statistically group and visualize the soft results for further analysis and study. A method is proposed to evaluate the decoding performance based on the density of the values of the soft outputs within the histogram. Results show that the performance is inversely related to the ratio of the values of the soft outputs within the near-zero bins within the histogram. The proposed method can be deployed at the decoder to provide an early indication of the reception and whether it has the potential to be correctly decoded or not. This early decision can save the decoding resources. 

Keywords

References

  1. M. Rowshan, M. Qiu, Y. Xie, X. Gu, and J. Yuan, "Channel Coding Toward 6G: Technical Overview and Outlook," IEEE Open Journal of the Communications Society, vol. 5, pp. 2585-2685, 2024.
  2. Y. Ding, L. Zhao, and J. Feng, "Turbo code optimization based on terahertz communication," Eighth International Conference on Electronic Technology and Information Science (ICETIS). SPIE, 2023.
  3. B. Le Gal and C. Jego, "Low-latency and high-throughput software turbo decoders on multi-core architectures," (in en), Ann. Telecommun., vol. 75, no. 1, pp. 27-42, 2020/02/01/2020.
  4. S. Weithoffer, G. Aousaji, J. Nadal, and C. A. Nour, "Iteration Overlap for Low-Latency Turbo Decoding," in 12th International Symposium on Topics in Coding (ISTC), 4-8 Sept. 2023, pp. 1-5.
  5. Z. Liu, R. Liu, H. Zhang, N. Wang, L. Sun, and J. Wang, "Parallel implementation of the CCSDS turbo decoder on GPU," China Communications, pp. 1-8, 2023.
  6. S. Saito, K. Fujimoto, and A. Shiraga, "Low-latency remote-offloading system for accelerator," Ann. Telecommun., vol. 79, no. 3, pp. 179-196, 2024/04/01 2024.
  7. X.-G. Xia, "Understanding turbo codes: A signal processing study," Journal of Information and Intelligence, vol. 2, no. 1, pp. 1-13, 01/2024.
  8. E. Yoon, S. Kwon, and S. Y. Kim, "An Efficient Application of Turbo Coding for OFDM In-Phase/Quadrature Index Modulation," IEEE Access, vol. 11, pp. 37031-37040, 2023.
  9. R. D. Agustin, I. G. P. Astawa, and A. Pratiarso, "Performance Analysis of Turbo Coding Implementation in MIMO Based DVB-T2 System," 2020 International Electronics Symposium (IES), 29-30 Sept. 2020, pp. 179-183.
  10. A. Alashqar, J. Alkasassbeh, R. Mesleh, and A. Al-Qaisi, "SDR implementation and real-time performance evaluation of 5G channel coding techniques," AEU - International Journal of Electronics and Communications, vol. 170, p. 154852, 2023/10/01/ 2023.
  11. M. Wei, D. Ren, and Q. Huang, "Design and Implementation of Low-Rate Turbo Coding and Decoding," 2024 IEEE/CIC International Conference on Communications in China (ICCC), 7-9 Aug. 2024, pp. 450-454.
  12. S. Miao et al., "Trends in Channel Coding for 6G," Proceedings of the IEEE, pp. 1-23, 2024.
  13. S. Vijayalakshmi, A. Paramasivam, S. Sakthivel, S. Kudiyarasan, E. Sankaran, and V. Nagarajan, "Design of high-speed data transfer turbo code for body channel communication transceivers," International Journal of Communication Systems, vol. 36, no. 7, p. e5447, 2023.
  14. C. Zhang, Y. Lin, D. Wang, and J. Hu, "Design of Low-Power Turbo Encoder and Decoder for NB-IoT," Chinese Journal of Electronics, vol. 33, no. 2, pp. 403-414, 2024.
  15. G. Zhao, "Dissecting and Implementing SOYA Algorithm Variations in Convolutional and Turbo Code Decoding: An Analytical Approach," 4th Asia-Pacific Conference on Communications Technology and Computer Science (ACCTCS), 24-26 Feb. 2024, pp. 780-785.
  16. Y. Shen, Y. Ren, A. T. Kristensen, X. You, C. Zhang, and A. Burg, "Improved Belief Propagation Decoding of Turbo Codes," ICASSP - IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 4-10 June 2023, pp. 1-5.
  17. R. Umar, F. Yang, H. Xu, and S. Mughal, "Distributed turbo coded spatial modulation based on code matched interleaver for MIMO system," Wireless Networks, vol. 29, no. 5, pp. 1995-2013, 2023/07/01 2023.
  18. J. Wang and Z. Wang, "Research on Parallel Turbo Encoding and Decoding Technology," IEEE 6th Advanced Information Management, Communicates, Electronic and Automation Control Conference (IMCEC), 24-26 May 2024, vol. 6, pp. 1378-1381.
  19. D. V. Linh and V. V. Yem, "A turbo-based encryption and coding scheme for multiple-input multiple-output orthogonal frequency division multiplexing wireless communica-tion systems affected by Doppler frequency offset," IET Communications, vol. 17, no. 5, pp. 632-640, 2023.
  20. A.-M. Cuc, F. L. Morgos, and C. Grava, "Perfor-mance Analysis of Turbo Codes, LDPC Codes, and Polar Codes over an AWGN Channel in the Presence of Inter Symbol Interference," Sensors, vol. 23, no. 4, p. 1942, 2023.
  21. L. C. Perez, J. Seghers, and D. J. Costello, "A Distance Spectrum Interpretation of Turbo Codes," IEEE Transactions on Information Theory, vol. 42, no. 6, pp. 1698-1709, 1996.
  22. P. Robertson, "Illuminating the structure of code and decoder of parallel concatenated recursive systematic (turbo) codes," in IEEE GLOBECOM. Communications: The Global Bridge, 1994/11, vol. 3, pp. 1298-1303.
  23. L. Bahl, J. Cocke, F. Jelinek, and J. Raviv, "Optimal decoding of linear codes for minimizing symbol error rate," (in English), IEEE Transactions on Information Theory, vol. 20, no. 2, pp. 284-287, 1974/03// 1974.
  24. I. European Telecommunications Standards, "Technical Specification; LTE; Evolved Universal Terrestrial Radio Access (E-UTRA), Multiplexing and channel coding (3GPP TS 36.212 version 16.2.0 Release 16)," 2020 2020.
  25. P. Robertson, E. Villebrun, and P. Hoeher, "A comparison of optimal and sub-optimal MAP decoding algorithms operating in the log domain," IEEE International Conference on Communications, 1995/06, vol. 2, pp. 1009-1013 vol.2.
  26. M. AlMahamdy and J. Dill, "Half-Iteration Early Termination of Turbo Decoding," IEEE 7th Annual Computing and Communication Workshop and Conference (CCWC), 2017/01/09/11, Las Vegas, NV USA: IEEE, pp. 591-595.
  27. M. AlMahamdy and J. Dill, "Early Termin-ation of Turbo Decoding by Identification of Undecodable Blocks," EEE Wireless Communications and Networ-king Confere-nce (WCNC), 2017/03/19/22 2017, San Francisco, CA USA: IEEE.
  28. M. A. H. AlMahamdy, "New Methods to Reduce Turbo Decoding Latency and the Complexity of Bit Insertion Techniques," Ohio University, 2017.