Adaptive Decision Feedback Channel Estimation with Periodic Phase Correction for Frequency-Domain Equalization in DS-CDMA Mobile Radios

Le LIU  Fumiyuki ADACHI  

Publication
IEICE TRANSACTIONS on Communications   Vol.E90-B   No.8   pp.1997-2005
Publication Date: 2007/08/01
Online ISSN: 1745-1345
DOI: 10.1093/ietcom/e90-b.8.1997
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Transmission Systems and Transmission Equipment for Communications
Keyword: 
DS-CDMA,  frequency-domain equalization,  adaptive decision feedback,  channel estimation,  

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Summary: 
Recently, the decision feedback channel estimation based on the minimum mean square error criterion (DF-MMSE-CE) using a fixed DF filter coefficient has been proposed to improve the channel estimation accuracy for DS-CDMA with frequency-domain equalization (FDE). In this paper, we propose adaptive DF (ADF)-MMSE-CE, in which the DF filter coefficient is adapted to changing channel conditions based on a recursive least square (RLS) algorithm. Furthermore, the channel estimate is phase corrected upon the reception of the periodically inserted pilot chip blocks. The average BER performance of DS-CDMA with MMSE-FDE using ADF-MMSE-CE is evaluated by computer simulation in a frequency-selective Rayleigh fading channel and the simulation results show that our proposed scheme is very robust against fast fading.