Improved Successive Detector for OFDM in Time-Variant Multipath Channels

Feng LI  Shihua ZHU  Mei RONG  

IEICE TRANSACTIONS on Communications   Vol.E92-B   No.5   pp.1892-1896
Publication Date: 2009/05/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.E92.B.1892
Print ISSN: 0916-8516
Type of Manuscript: LETTER
Category: Wireless Communication Technologies
OFDM,  channel equalization,  time-varying channels,  successive detector,  

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Time variations of wireless multipath channels can lead to severe intercarrier interference (ICI) in orthogonal frequency division multiplex (OFDM) systems, whereas large Doppler frequency spread can provide us with time diversity gain. In order to take advantage of the time diversity and to suppress the interference and noise enhancement at the same time, the receiver normally detects the data successively. In this letter, we propose an improved detection ordering based on the log-likelihood ratio (LLR) rather than the signal-to-noise ratio (SNR) for the successive detector. Using both theoretical analysis and computer simulation, it is shown that this scheme outperforms the traditional successive detection methods.