• Title/Summary/Keyword: OFDMA/CDM

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Performance Enhancement of an OFDMA/CDM-based Cellular System in a Multi-Cell Environment (다중셀 환경에서 OFDMA/CDM 기반 셀룰라 시스템의 성능 개선)

  • Kim, Duk-Kyung;Ryu, Je-Hun;Jeong, Bu-Seop
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.7A
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    • pp.587-596
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    • 2005
  • In this paper, we propose an OFDMA/CDM-based cellular system, which accommodates multiple users in frequency-domain and multiplexes user data with frequency-domain spreading. The proposed system utilizes random codes to discriminate cells and adopts the pre-equalization to enhance the performance. For cellular applications, a number of pre-equalization techniques are compared and an efficient power allocation scheme is suggested with a transmit power constraint. Especially, the validity of OFDMA/CDM based cellular system is investigated, by comparing the performance for varying the number of multiplexed data symbols at different locations. Finally the pre/post-equalization is proposed to reduce the performance degradation caused by time delay.