KSII Transactions on Internet and Information Systems (TIIS)

Korean Society for Internet Information (한국인터넷정보학회)
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Selective Demodulation Scheme Based on Log-Likelihood Ratio Threshold

  • Huang, Yuheng (Department of Electronics and Information Engineering, Huazhong University of Science &Technology) ;
  • Dong, Yan (Department of Electronics and Information Engineering, Huazhong University of Science &Technology) ;
  • Jo, Minho (Department of Computer and Communication, Korea University) ;
  • Liu, Yingzhuang (Department of Electronics and Information Engineering, Huazhong University of Science &Technology)
  • Received : 2012.01.06
  • Accepted : 2013.03.29
  • Published : 2013.04.30
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Abstract

This paper aims at designing a selective demodulation scheme based on Log-likelihood Ratio threshold (SDLT) instead of the conventional adaptive demodulation (ADM) scheme, by using rateless codes. The major difference is that the Log-likelihood ratio (LLR) threshold is identified as a key factor to control the demodulation rate, while the ADM uses decision region set (DRS) to adjust the bit rate. In the 16-QAM SDLT scheme, we deduce the decision regions over an additive white Gaussian channel, corresponding to the variation of LLR threshold and channel states. We also derived the equations to calculate demodulation rate and bit error rate (BER), which could be proven by simulation results. We present an adaptation strategy for SDLT, and compare it with ADM and adaptive modulation (AM). The simulation results show that our scheme not only significantly outperforms the ADM in terms of BER, but also achieves a performance as good as the AM scheme. Moreover, the proposed scheme can support much more rate patterns over a wide range of channel states.

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References

  1. Jahon Koo and Kwangsue Chung, "A Mobile-aware Adaptive Rate Control Scheme for Improving the User Perceived QoS of Multimedia Streaming Services in Wireless Broadband Networks," KSII Transactions on Internet and Information Systems, vol. 4, no. 6, pp. 1152-1168, Dec, 2010.
  2. J. Goldsmith and S. Chua, "Variable-rate variable-power MQAM for fading channels," IEEE Transactions on Communication, vol. 45, no. 10, pp. 1218-1230, Oct, 1997. https://doi.org/10.1109/26.634685
  3. L. Toni, "Does Fast Adaptive Modulation Always Outperform Slow Adaptive modulation," IEEE Transactions on Wireless Communications, vol 10, no. 5, pp. 1504-1513, May, 2011. https://doi.org/10.1109/TWC.2011.020111.100643
  4. H. Bischi, H. Brandt and T. Cola, "Adaptive coding and modulation for satellite broadband networks: theory and practice," Wiley Int. J. Satell. Commun. Netw, vol. 28, no. 2, pp. 59-111, April, 2010.
  5. A. Ljaz, A. Awosyila and B. Evans, "Signal-to-noise ratio estimation algorithm for adaptive coding and modulation in advanced digital video broadcasting-radar cross section satellite systems," IET Communications, vol. 6, no. 11, pp. 1587-1593, July, 2012. https://doi.org/10.1049/iet-com.2010.0938
  6. S. Sesia, G. Caire, and G. Vivier, "Incremental redundancy Hybrid ARQ schemes based on low-density parity-check codes," IEEE Transactions on Communication, vol. 52, no. 8, pp. 1311-1321, Aug, 2004. https://doi.org/10.1109/TCOMM.2004.833022
  7. Sangjoon Park and Younghoon Whang, "Extended Detection for MIMO Systems with Partial Incremental Redundancy Based Hybrid ARQ," IEEE Transactions on Wireless Communications, vol 11, no. 10, pp. 3714-3722, Oct, 2012. https://doi.org/10.1109/TWC.2012.081612.112299
  8. S. Q. Hu, Y. D. Yao and A. U. Sheikh, "Tagged user approach for finite-user finite-buffer S-Aloha analysis in AWGN and frequency selective fading channels," in Proc. of 34th IEEE Sarnoff Symposium, pp. 1-5, May, 2011.
  9. Y. H. Huang, Y. Dong and Y. Z. Liu, "A New Rate Adaptive System: Controlled Solf Demodulation," in Proc. of IEEE Computing Communications and Applications. HongKong, China, pp. 360-364, Jan, 2012.
  10. J. D. Brown, S. Pasupathy and K. N. Plataniotis, "Adaptive demodulation using rateless erasure codes," IEEE Transactions on Communication, vol. 54, no. 9, Sep, 2006.
  11. J. D. Brown, J. Abouei and K. N. Plataniotis, "Adaptive demodulation in differentially coherent phase systems: Design and performance analysis," IEEE Transactions on Communication, vol. 59, pp. 1772-1778, May, 2011. https://doi.org/10.1109/TCOMM.2011.051311.100331
  12. M. Luby, "LT codes," in Proc. of 43rd Symp. Found. Comput. Sci., Vancouver, BC, Canada, pp. 271-282, Nov, 2002.
  13. A. Shokrollahi, "Raptor codes," IEEE Trans .Inf. Theory, vol. 52, no. 6, pp. 2551-2567. June, 2006. https://doi.org/10.1109/TIT.2006.874390
  14. Y. J. Fan and L. F. Lai, "Rateless coding for MIMO fading channels: Performance limits and code construction," IEEE Trans. Wireless Commun, vol. 9, no. 4, pp. 1288-1292, April, 2010. https://doi.org/10.1109/TWC.2010.04.090780
  15. Sivasubramanian and H. Leib, "Fixed-rate raptor codes over Rician fading channels," IEEE Trans. Veh. Technol, vol. 57, no. 6, pp. 3905-3911, Nov, 2008. Article (CrossRef Link) https://doi.org/10.1109/TVT.2008.923664
  16. Hagh, M. J and Soleymani, "Application of Raptor Coding With Power Adaptation to DVB Multiple Access Channels," IEEE Trans. Broadcasting, vol. 58, no. 3, pp. 379-389, Sep, 2012. https://doi.org/10.1109/TBC.2012.2197449
  17. S. Y. Legoff, "Signal constellations for bit-interleaved coded modulation," IEEE Trans. Inf. Theory, vol. 49, no. 1, pp. 307-313, Jan, 2003. https://doi.org/10.1109/TIT.2002.806152