Performance of Coherent Multi-Carrier/DS-CDMA and MC-CDMA for Broadband Packet Wireless Access

Sadayuki ABETA
Fumiyuki ADACHI

IEICE TRANSACTIONS on Communications   Vol.E84-B    No.3    pp.406-414
Publication Date: 2001/03/01
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Innovative Mobile Communication Technologies at the Dawn of the 21st Century)
broadband packet wireless access,  single-carrier/DS-CDMA,  multi-carrier/DS-CDMA,  multicarrier CDMA,  

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This paper compares the packet error rate (PER) performance of three access schemes, i.e., single-carrier (SC)/DS-CDMA, multi-carrier (MC)/DS-CDMA, and MC-CDMA assuming an 80-MHz bandwidth in order to achieve an optimum broadband packet wireless access scheme. In a broadband propagation channel, severe multipath interference degrades the accuracy of timing detection of multipath components (path search) and channel estimation required for coherent detection. Computer simulation results show that, in the reverse link, SC/DS-CDMA achieves better performance than MC/DS-CDMA because the pilot signal power in one sub-carrier required for path search and channel estimation decreases as the number of sub-carriers increases. The superiority of MC-CDMA to MC (SC)/DS-CDMA in the forward link is also demonstrated, because frequency diversity is effectively utilized in association with the mitigation of a much longer symbol duration than the delay spread in MC-CDMA, meanwhile a higher degree of multipath interference offsets the Rake time diversity in MC (SC)/DS-CDMA in a broadband multipath fading channel.