TR2005-075

Symbol Spreading for Ultrawideband Systems Based on Multiband OFDM


    •  Ramachandran, I., Nakache, Y.-P., Orlik, P., Molisch, A.F., Zhang, J., "Symbol Spreading for Ultrawideband Systems Based on Multiband OFDM", IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), September 2004, vol. 2, pp. 1204-1209.
      BibTeX TR2005-075 PDF
      • @inproceedings{Ramachandran2004sep,
      • author = {Ramachandran, I. and Nakache, Y.-P. and Orlik, P. and Molisch, A.F. and Zhang, J.},
      • title = {Symbol Spreading for Ultrawideband Systems Based on Multiband OFDM},
      • booktitle = {IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)},
      • year = 2004,
      • volume = 2,
      • pages = {1204--1209},
      • month = sep,
      • url = {https://www.merl.com/publications/TR2005-075}
      • }
  • MERL Contacts:
  • Research Area:

    Communications

Abstract:

We investigate the effect of symbol spreading on the performance of ultrawideband systems based on multiband OFDM. Ultrawideband channels offer the possibility of very high frequency diversity, as the used handwidth is much larger than the coherence bandwidth of the channel. In multiband-OFDM, frequency diversity stems from (i) forward error correction coding, which distributes the symbols associated with one bit among different tones, and (ii) interleaving, which distributes the symbols among different employed frequency bands. We show that for weak (rate 3/4) error correcting codes, the achieved diversity order is insufficient. However, the use of Walsh-Hadamard spreading gives additional diversity within each frequency band and greatly improves the performance. Furthermore, we propose a novel scheme for grouping OFDM tones before the spreading is performed. This grouping gives additional flexibility in the system design.

 

  • Related News & Events

    •  NEWS    PIMRC 2004: 2 publications by Philip V. Orlik, Jinyun Zhang and others
      Date: September 5, 2004
      Where: IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)
      MERL Contacts: Jinyun Zhang; Philip V. Orlik
      Brief
      • The papers "Adaptive Transmit Diversity with Quadrant Phase Constraining Feedback" by Wu, J., Horng, H., Zhang, J., Molisch, A. and Xiao, C. and "Symbol Spreading for Ultrawideband Systems Based on Multiband OFDM" by Ramachandran, I., Nakache, Y.-P., Orlik, P., Molisch, A. F. and Zhang, J. were presented at the IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC).
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