Improving ADSL Performance with Selective QAM Mapping and Hybrid ARQ

A B N Goolamhossen, T P Fowdur

Abstract


Asymmetric Digital Subscriber Line (ADSL) is a high-rate transmission standard used for broadband access. Error performance and bandwidth efficiency are the two main concerns in ADSL transmission, hence prompting the need for appropriate techniques to provide improved error protection and noise robustness in ADSL systems. This paper proposes an enhanced ADSL transmission model which incorporates Trellis Coded Modulation (TCM), selective or prioritised QAM constellation mapping and Hybrid Automatic Repeat reQuest HARQ with diversity combining. Simulation results demonstrate that the proposed scheme provides a significant gain of over 3 dB in Eb/No over a conventional ADSL system which does not use HARQ. It also achieves a 30 percent gain in throughput over a conventional ADSL which uses HARQ without diversity combining.

Keywords: ADSL, Selective QAM, TCM, HARQ, Diversity Combining.

Cite as:A B N Goolamhossen, T P Fowdur "Improving ADSL Performance with Selective QAM Mapping and Hybrid ARQ ", ADBU J.Engg.Tech., 2(1)(2015) 0021103(7pp)


Full Text:

PDF

References


ALLIED TELESIS, 2007. DSL White Paper, Available: http://www.alliedtelesis.com/media/pdf/dsl_wp.pdf

TELECOMMUNICATION DEVELOPMENT BUREAU ITU-D Study Groups, 2001, “Report on Xdslâ€, Geneva, 2001.

D.Toumpakaris, Y.Wei, J.M. Cioffi, D. Gardan, M. Ouzzif, “A byte-erasure method for improved impulse immunity in DSL systems using soft information from an inner codeâ€, IEEE International Conference on Communications, ICC '03, May 2003, Volume 4, pp.2431 -2435.

M. Hyll, “Reduced complexity bit allocation to subchannels in a multi-carrier, high speed data transmission systemâ€, Sweden,1999, Patent No. 935,529.

Y.Zhao, K. Ho-Van, and T. Le-Ngoc, “Efficient erasure marking technique for interleaving delay reduction in DSL systems impaired by impulse noiseâ€, Ottawa, ON, 2012 pp. 3170 - 3174.

N. Papanderou, and T. Antonakopoulos, T, “A new computationally efficient discrete bit-loading algorithm for DMT applicationsâ€, IEEE Transactions in Communications, May 2005, 53(5), pp. 785 - 789.

G. Ungerboeck, “Channel coding with multilevel/phase signalsâ€, IEEE Transactions in Information Theory, January 1982, 28(1), pp. 55-67.

G.D. Forney, “Efficient Modulation for Band-Limited Channels†IEEE Selected Areas in Communications, September 1984, 2(5), pp. 632 - 647.

L.F.Wei, “Rotationally Invariant Convolutional Channel Coding with Expanded Signal Space - Part II: Nonlinear Codesâ€, IEEE Selected Areas in Communications, September 1984, 2(5), pp. 672-686.

L.F. Wei, “Trellis-coded modulation with multidimensional constellationsâ€, IEEE Transactions in Information Theory, July 1987, 33(4), pp. 483-501.

R.Boden, “Real-Time ARQ Protocol for Improved Impulsive Noise Robustness of ADSL Systemsâ€, Proceedings of 3rd EuroNGI Conference on Next Generation Internet Networks, Trondheim 07, pp. 40 - 47.

M. Isaka, R.H. Morelos-Zaragoza, M.P.C. Fossorier, and Shu Lin “Multilevel coded 16-QAM modulation with multistage decoding and unequal error protectionâ€, Globecom, 1998, Sydney NSW, pp. 3548-3553.

P. Vaidyanathan, Y.Lin, S. Akkarakaran and S.M. Phoong, “Discrete Multi-tone Modulation with Principalâ€, IEEE Transactions on Circuits and Systems-I: Fundamental Theory and Applications, 2002, 49(10), pp. 1397-1412.

N.Souto, R.Dinis, J.C. Silva, and F.Cercas, “Impact of Imperfect Channel Estimation on the Performance of MQAM Hierarchical Constellations with Diversityâ€, Honolulu, 2007, pp. 1095-2055.

T.P. Fowdur, Y. Beeharry and K.M.S Soyjaudah, “Performance of LTE Turbo Codes with Joint Source Channel Decoding, Adaptive Scaling and Prioritised QAM Constellation Mappingâ€, International Journal on Advances in Telecommunications, vol 6 no 3 & 4, 2013, pp.143-152.

H. Lüders, A. Minwegen, and P. Vary, “Improving UMTSLTE Performance by UEP in High Order Modulationâ€, 7thInternational Workshop on Multi-Carrier Systems & Solutions (MC-SS 2009), Herrsching, Germany, 2009, pp.185-194.

M.I.Sheik Mamode, T.P. Fowdur and K.M.S. Soyjaudah, “Performance Analysis of ADSL Data Transmission†UNIVERSITY OF MAURITIUS RESEARCH JOURNAL – Volume 18 – 2012, University of Mauritius, Réduit, Mauritius, pp. 77-93.

B.Sklar, “Digital Communications: Fundamentals and Applicationsâ€, Prentice-Hall International Inc., 1988.

A. J. Viterbi, “Convolutional codes and their performance in communication systemsâ€, IEEE Trans. on Commun., Vol. 19, No 5, pp. 751-772, 1971.

Y. Jiang, A Practical Guide to Error-Control Coding Using MATLAB, 1 ed., Artech House, 2010.

Q. Zhang and S. A. Kassam, "Hybrid ARQ with selective combining for fading channels," IEEE Journal on Selected Areas in Communications, vol. 17, no. 5, pp. 867-874, May 1999.


Refbacks

  • There are currently no refbacks.


------------------------------------------------------------------------------------------------------------------------

The ADBU Journal of Engineering Technology (AJET)" ISSN:2348-7305

This journal is published under the terms of the Creative Commons Attribution (CC-BY) (http://creativecommons.org/licenses/)

Number of Visitors to this Journal: