Open Access

A Heuristic Optimal Discrete Bit Allocation Algorithm for Margin Maximization in DMT Systems

EURASIP Journal on Advances in Signal Processing20072007:012140

Received: 14 July 2006

Accepted: 25 December 2006

Published: 13 March 2007


A heuristic optimal discrete bit allocation algorithm is proposed for solving the margin maximization problem in discrete multitone (DMT) systems. Starting from an initial equal power assignment bit distribution, the proposed algorithm employs a multistaged bit rate allocation scheme to meet the target rate. If the total bit rate is far from the target rate, a multiple-bits loading procedure is used to obtain a bit allocation close to the target rate. When close to the target rate, a parallel bit-loading procedure is used to achieve the target rate and this is computationally more efficient than conventional greedy bit-loading algorithm. Finally, the target bit rate distribution is checked, if it is efficient, then it is also the optimal solution; else, optimal bit distribution can be obtained only by few bit swaps. Simulation results using the standard asymmetric digital subscriber line (ADSL) test loops show that the proposed algorithm is efficient for practical DMT transmissions.


Information TechnologyQuantum InformationAllocation SchemeMaximization ProblemAllocation Algorithm


Authors’ Affiliations

Department of Electronic Engineering, School of Information Science and Technology, Tsinghua University, Beijing, China
National Key Laboratory of Space Microwave Technology, Xi'an Institute of Space Radio Technology, Xi'an, China


  1. Cioffi JM, Oksman V, Werner J-J, et al.: Very-high-speed digital subscriber lines. IEEE Communications Magazine 1999,37(4):72-79. 10.1109/35.755453View ArticleGoogle Scholar
  2. Bingham JAC: ADSL, VDSL, and Multicarrier Modulation. John Wiley & Sons, New York, NY, USA; 2000.View ArticleGoogle Scholar
  3. Del Re E, Fantacci R, Morosi S, Seravalle R: Comparison of CDMA and OFDM techniques for downstream power-line communications on low voltage grid. IEEE Transactions on Power Delivery 2003,18(4):1104-1109. 10.1109/TPWRD.2003.817517View ArticleGoogle Scholar
  4. Cioffi JM: Advanced Digital Communication. EE379C Course Textbook, Stanford University, 2002Google Scholar
  5. Hughes-Hartogs D: Ensemble modem structure for imperfect transmission media. U.S. Patents, 4,679,227 (July 1987), 4,731,816 (March 1988), and 4,833,706 (May 1989)Google Scholar
  6. 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(2–4):773-775.View ArticleGoogle Scholar
  7. Piazzo L: Fast algorithm for power and bit allocation in OFDM systems. Electronics Letters 1999,35(25):2173-2174. 10.1049/el:19991516View ArticleGoogle Scholar
  8. Piazzo L: Fast optimal bit-loading algorithm for adaptive OFDM systems. In Internal Report 002-04-03. INFOCOM Department, University of Rome, Rome, Italy; 2003.Google Scholar
  9. 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. 10.1109/26.818869View ArticleGoogle Scholar
  10. Campello J: Optimal discrete bit loading for multicarrier modulation systems. Proceedings of IEEE International Symposium on Information Theory, August 1998, Cambridge, Mass, USA 193.Google Scholar
  11. Levin HE: A complete and optimal data allocation method for practical discrete multitone systems. Proceedings of IEEE Global Telecommunications Conference (GLOBECOM '01), November 2001, San Antonio, Tex, USA 1: 369-374.View ArticleGoogle Scholar
  12. Sonalkar RV, Shively RR: An efficient bit-loading algorithm for DMT applications. IEEE Communications Letters 2000,4(3):80-82. 10.1109/4234.831031View ArticleGoogle Scholar
  13. Fasano A: On the optimal discrete bit loading for multicarrier systems with constraints. Proceedings of the 57th IEEE Semiannual Vehicular Technology Conference (VTC '03), April 2003, Jeju, South Korea 2: 915-919.MathSciNetGoogle Scholar
  14. Papandreou N, Antonakopoulos T: A new computationally efficient discrete bit-loading algorithm for DMT applications. IEEE Transactions on Communications 2005,53(5):785-789. 10.1109/TCOMM.2005.847141View ArticleGoogle Scholar
  15. Long T, Cioffi JM, Liu F: XDSL Technology and Applications. Publishing House of Electronics Industry, Beijing, China; 2002.Google Scholar
  16. Manber U: Introduction to Algorithms: A Creative Approach. Pearson Education Asia Limited and Publishing House of Electronics Industry, Beijing, China; 2005.MATHGoogle Scholar


© Li-Ping Zhu et al. 2007

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.