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  • Research Article
  • Open Access

Outage Performance of Flexible OFDM Schemes in Packet-Switched Transmissions

EURASIP Journal on Advances in Signal Processing20092009:698417

  • Received: 30 January 2009
  • Accepted: 7 August 2009
  • Published:


α-OFDM, a generalization of the OFDM modulation, is proposed. This new modulation enhances the outage capacity performance of bursty communications. The α-OFDM scheme is easily implementable as it only requires an additional time symbol rotation after the IDFT stage and a subsequent phase rotation of the cyclic prefix. The physical effect of the induced rotation is to slide the DFT window over the frequency spectrum. When successively used with different angles α at the symbol rate, α-OFDM provides frequency diversity in block fading channels. Interestingly, simulation results show a substantial gain in terms of outage capacity and outage BER in comparison with classical OFDM modulation schemes. The framework is extended to multiantenna and multicellular OFDM-based standards. Practical simulations, in the context of 3GPP-LTE, called hereafter α-LTE, sustain our theoretical claims.


  • Prefix
  • Fading Channel
  • Modulation Scheme
  • Cyclic Prefix
  • Capacity Performance

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Authors’ Affiliations

Algorithm Group, ST-Ericsson, 635 Route des Lucioles, 06560 Sophia-Antipolis, France
Department of Telecommunication, Alcatel Lucent Chair on Flexible Radio, Supélec, 3 rue Joliot Curie, 91192 Gif sur Yvette, France


© R. Couillet and M. Debbah. 2009

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.