Frequency-interleaved CDMA uplink transmission using frequency-domain equalization

Kazuaki Takeda, Fumiyuki Adachi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Citations (Scopus)


The downlink bit error rate (BER) performances of DS- and MC-CDMA in a frequency-selective fading channel can be significantly improved by the use of frequency-domain equalization (FDE) based on minimum mean square error (MMSE) criterion. However, the uplink BER performance degrades due to strong multi-user interference (MUI). In this paper, we propose frequency-interleaved CDMA using MMSE-FDE, in which the subcarrier components of each user's CDMA signal are interleaved onto wider bandwidth. Then, the frequency-interleaved CDMA signal is transformed into a time-domain signal by the inverse fast Fourier transform (IFFT). Interleaving patterns assigned to different users are orthogonal each other. The proposed scheme can avoid the MUI completely while achieving frequency diversity gain due to MMSE-FDE. It is shown by computer simulation that the use of frequency-interleaving can significantly improve the uplink BER performance in a frequency-selective Rayleigh fading channel.

Original languageEnglish
Title of host publicationVTC 2005-Fall
Subtitle of host publicationMid Way Through the Decade - Technology Past, Present and Future
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages5
ISBN (Electronic)0780391527
Publication statusPublished - 2005
Externally publishedYes
Event62nd Vehicular Technology Conference, VTC 2005 - Dallas, United States
Duration: 2005 Sept 252005 Sept 28

Publication series

NameIEEE Vehicular Technology Conference
ISSN (Print)1550-2252


Other62nd Vehicular Technology Conference, VTC 2005
Country/TerritoryUnited States


  • CDMA
  • Component
  • Frequencyinterleaving

ASJC Scopus subject areas

  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Applied Mathematics


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