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Fine-Granularity Loading Schemes Using Adaptive Reed-Solomon Coding for xDSL-DMT Systems


While most existing loading algorithms for xDSL-DMT systems strive for the optimal energy distribution to maximize their rate, the amounts of bits loaded to subcarriers are constrained to be integers and the associated granularity losses can represent a significant percentage of the achievable data rate, especially in the presence of the peak-power constraint. To recover these losses, we propose a fine-granularity loading scheme using joint optimization of adaptive modulation and flexible coding parameters based on programmable Reed-Solomon (RS) codes and bit-error probability criterion. Illustrative examples of applications to VDSL-DMT systems indicate that the proposed scheme can offer a rate increase of about in most cases as compared to various existing integer-bit-loading algorithms. This improvement is in good agreement with the theoretical estimates developed to quantify the granularity loss.


  1. 1.

    Cioffi JM: A Multicarrier Primer. ANSI T1E1.4 Committee Contribution, pp. 91–157, November, 1991

    Google Scholar 

  2. 2.

    Asymmetric Digital Subscriber Line (ADSL) Metallic Interface ANSI Std. T1.413-1998, 1998

  3. 3.

    Very-high Speed Digital Subscriber Lines (VDSL) Metallic Interface ANSI Std. T1E1.4/2003-210R5, 2003

  4. 4.

    Gallager RG: Information Theory and Reliable Communication. John Wiley & Sons, New York, NY, USA; 1968.

    Google Scholar 

  5. 5.

    Chow PS: Bandwidth optimized digital transmission techniques for spectrally shaped channels with impulse noise, Ph.D. dissertation. Stanford University, Stanford, Calif, USA; 1993.

    Google Scholar 

  6. 6.

    Leke A, Cioffi JM: A maximum rate loading algorithm for discrete multitone modulation systems. Proceedings of IEEE Global Telecommunications Conference (GLOBECOM '97), November 1997, Phoenix, Ariz, USA 3: 1514–1518.

    Article  Google Scholar 

  7. 7.

    Baccarelli E, Fasano A, Biagi M: Novel efficient bit-loading algorithms for peak-energy-limited ADSL-type multicarrier systems. IEEE Transactions on Signal Processing 2002, 50(5):1237–1247. 10.1109/78.995090

    Article  Google Scholar 

  8. 8.

    Spectrum Management for Loop Transmission Systems ANSI Std. T1.417-2001, January 2001

  9. 9.

    Hughes-Hartogs D: Ensemble modem structure for imperfect transmission media. U.S. Patents nos. 4,679,227 (July 1987), 4,731,816 (March 1988) and 4,833,706 (May 1989)

    Google Scholar 

  10. 10.

    Krongold BS, Ramchandran K, Jones DL: Computationally efficient optimal power allocation algorithms for multicarrier communication systems. IEEE Transactions on Communications 2000, 48(1):23–27. 10.1109/26.818869

    Article  Google Scholar 

  11. 11.

    Baccarelli E, Biagi M: Optimal integer bit-loading for multicarrier ADSL systems subject to spectral-compatibility limits. Signal Processing 2004, 84(4):729–741. 10.1016/j.sigpro.2003.12.004

    Article  Google Scholar 

  12. 12.

    Jang J, Lee KB, Lee Y-H: Transmit power and bit allocations for OFDM systems in a fading channel. Proceedings of IEEE Global Telecommunications Conference (GLOBECOM '03), December 2003, San Francisco, Calif, USA 2: 858–862.

    Article  Google Scholar 

  13. 13.

    Chow PS, Cioffi JM, Bingham JAC: A practical discrete multitone transceiver loading algorithm for data transmission over spectrally shaped channels. IEEE Transactions on Communications 1995, 43(234):773–775.

    Article  Google Scholar 

  14. 14.

    Oppenheim AV, Schafer RW, Buck JR: Discrete-Time Signal Processing. 2nd edition. Prentice-Hall, Englewood Cliffs, NJ, USA; 1998. (Sec. 4.8.3. Analysis of Quantization Errors)

    Google Scholar 

  15. 15.

    Moroles-Zaragoza RH: The Art of Error Control Coding. John Wiley & Sons, New York, NY, USA; 2000.

    Google Scholar 

  16. 16.

    Zhang L, Gao C, Cao Z: Exact analysis of bit error rate of maximum-distance-separable codes. Proceedings of IEEE Global Telecommunications Conference (GLOBECOM '00), November–December 2000, San Francisco, Calif, USA 2: 816–819.

    Article  Google Scholar 

  17. 17.

    Telcordia Technologies : Proposed Bit Rates for Spectral Compatibility with VDSL. ANSI T1E1.4 Committee Contribution, T1E1.4/2002-159R2, August 2002

  18. 18.

    Hasan MA, Bhargava VK: Architecture for a low complexity rate-adaptive Reed-Solomon encoder. IEEE Transactions on Computers 1995, 44(7):938–942. 10.1109/12.392853

    Article  Google Scholar 

  19. 19.

    Shayan YR, Le-Ngoc T: A cellular structure for a versatile Reed-Solomon decoder. IEEE Transactions on Computers 1997, 46(1):80–85. 10.1109/12.559805

    Article  Google Scholar 

  20. 20.

    Smith JG: Odd-bit quadrature amplitude-shift keying. IEEE Transactions on Communications 1975, 23(3):385–389. 10.1109/TCOM.1975.1092806

    Article  Google Scholar 

  21. 21.

    Cho K, Yoon D: On the general BER expression of one- and two-dimensional amplitude modulations. IEEE Transactions on Communications 2002, 50(7):1074–1080. 10.1109/TCOMM.2002.800818

    Article  Google Scholar 

  22. 22.

    VDSL Test Specification for VDSL Olympics ANSI T1E1.4 Contribution, T1E1.4/2003-036R4, February 2003

  23. 23.

    Lauer JP, Cioffi JM: A turbo trellis coded discrete multitone transmission system. Proceedings of IEEE Global Telecommunications Conference (GLOBECOM '99), December 1999, Rio de Janeireo, Brazil 5: 2581–2585.

    Google Scholar 

  24. 24.

    Kerpez KJ, Waring DL, Galli S, Dixon J, Madon P: Advanced DSL management. IEEE Communications Magazine 2003, 41(9):116–123. 10.1109/MCOM.2003.1232246

    Article  Google Scholar 

  25. 25.

    Song KB, Chung ST, Ginis G, Cioffi JM: Dynamic spectrum management for next-generation DSL systems. IEEE Communications Magazine 2002, 40(10):101–109. 10.1109/MCOM.2002.1039864

    Article  Google Scholar 

  26. 26.

    Cendrillon R, Yu W, Moonen M, Verlinden J, Bostoen T: Optimal multi-user spectrum management for digital subscriber lines. to appear in IEEE Transactions on Communications, to appear in IEEE Transactions on Communications,

  27. 27.

    Yu W, Ginis G, Cioffi JM: Distributed multiuser power control for digital subscriber lines. IEEE Journal on Selected Areas in Communications 2002, 20(5):1105–1115. 10.1109/JSAC.2002.1007390

    Article  Google Scholar 

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Correspondence to Saswat Panigrahi.

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Panigrahi, S., Le-Ngoc, T. Fine-Granularity Loading Schemes Using Adaptive Reed-Solomon Coding for xDSL-DMT Systems. EURASIP J. Adv. Signal Process. 2006, 065716 (2006).

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  • Information Technology
  • Data Rate
  • Rate Increase
  • Energy Distribution
  • Quantum Information