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Capacity Enhancement of DS-CDMA Downlink through Multicarrier with Frequency Overlapping

  • A. Gameiro

Abstract

We present a technique based on the frequency diversity inherent in direct sequence spread spectrum (DS-SS) signals that allows to extend the capacity of CDMA systems based on DS-SS. The proposal makes use of several sets of DS-SS signals modulated by carriers separated by a fraction of the chip rate, so that there is frequency overlap between adjacent sets. The frequency diversity of DS-SS signals allows the use of correlated frequency bands to cancel the inter-set interference. For the case of a frequency separation between the interfering and cancelling components equal to the chip rate, the process is code independent and can therefore be applied in the downlink. Numerical results show that non-negligible bandwidth savings can be achieved at the expense of a small noise penalty.

Keywords

CDMA System Wideband Code Division Multiple Access Direct Sequence Spread Spectrum Chip Rate Central Carrier 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. [1]
    S. Abeta, H. Atarashi and M. Sawaashi, “Forward link of coherent DS-CDMA and MC-CDMA Broadaband packet wireless in a multicell environment”, Proc. of VTC Fall, Sept. 2000, Boston.Google Scholar
  2. [2]
    L. B. Milstein, “Wideband Code Division Multiple access”, IEEE J on Selec. Areas on Commun., Aug. 2000, pp. 1344–1354Google Scholar
  3. [3]
    L. Gonçalves and A. Gameiro,“ Frequency Shift Based Multiple Access Interference Canceller for DS CDMA Signals”, to be presented at VTC 2001, Atlantic City,Oct. 2001.Google Scholar
  4. [4]
    A. Gameiro, “A cyclostationary approach to enhance the capacity of multipath synchronous CDMA channels ”, In preparation.Google Scholar

Copyright information

© Springer Science+Business Media New York 2002

Authors and Affiliations

  • A. Gameiro
    • 1
  1. 1.Dept. of Electronics and TelecUniversity of Aveiro / Institute TelecommunicationsPortugal

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