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  • Research Article
  • Open Access

Multilevel Codes for OFDM-Like Modulation over Underspread Fading Channels

EURASIP Journal on Advances in Signal Processing20062006:097210

  • Received: 7 June 2005
  • Accepted: 12 May 2006
  • Published:


We study the problem of modulation and coding for doubly dispersive, that is, time and frequency selective, fading channels. Using the recent result that underspread linear systems are approximately diagonalized by biorthogonal Weyl-Heisenberg bases, we arrive at a canonical formulation of modulation and code design. For coherent reception with maximum-likelihood decoding, we derive the code design criteria as a function of the channel's scattering function. We use ideas from generalized concatenation to design multilevel codes for this canonical channel model. These codes are based on partitioning a constellation carved out from the integer lattice. Utilizing the block fading interpretation of the doubly dispersive channel, we adapt these partitioning techniques to the richness of the channel. We derive an algebraic framework which enables us to partition in arbitrarily large dimensions.


  • Information Technology
  • Linear System
  • Quantum Information
  • Fading Channel
  • Canonical Formulation

Authors’ Affiliations

The Coordinated Science Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA


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© S. Mallik and R. Koetter. 2006

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.