Feng Li

Xi'an Jiaotong University, Ch’ang-an, Shaanxi, China

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Publications (4)1.67 Total impact

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    ABSTRACT: An improved soft-input soft-output (SISO) minimum mean-squared error (MMSE) detection method is proposed for joint coding and precoding OFDM systems under imperfect channel estimation. Compared with the traditional mismatched detection which uses the channel estimate as its exact value, the signal model of the proposed detector is more accurate and the influence of channel estimation error (CEE) can be effectively mitigated. Simulations indicate that the proposed scheme can improve the bit error rate (BER) performance with fewer pilot symbols.
    IEICE Transactions. 01/2010; 93-B:757-761.
  • Feng Li, Shihua Zhu, Mei Rong
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    ABSTRACT: This letter presents an iterative detection scheme for orthogonal frequency division multiplexing (OFDM) systems with imperfect channel state information (CSI). In deriving the proposed scheme, channel estimation error is combated by using the theory of variational inference. The proposed scheme deals with the channel impulse response parameters and detects the information symbols iteratively and jointly. The effectiveness of the new approach is demonstrated by Monte-Carlo simulations.
    IEEE Signal Processing Letters 06/2009; · 1.67 Impact Factor
  • Feng Li, Shihua Zhu, Mei Rong
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    ABSTRACT: 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.
    IEICE Transactions. 01/2009; 92-B:1892-1896.
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    ABSTRACT: An improved iterative minimum mean-squared error (MMSE) channel estimation method is proposed for joint coding and precoding OFDM systems. Compared with the traditional simplified estimator, the proposed scheme provides higher estimation quality with slight complexity increment at low signal-to-noise ratio (SNR) values. The performance of the iterative receiver including the proposed estimator approaches that of the perfect MMSE estimator without any simplification.
    IEICE Transactions. 01/2009; 92-B:2520-2524.