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[Author] Lei DU(4hit)

1-4hit
  • Access Probability Aware Cell Reselection for 3G Evolution

    Mingju LI  Lei DU  Lan CHEN  

     
    LETTER

      Vol:
    E92-B No:5
      Page(s):
    1825-1827

    In LTE, AC barring check is performed before RRC connection. In some cells with a low access probability, the UEs keep retrying access which results in higher connection failure and longer access delay. We therefore propose balancing the UEs by adjusting the cell reselection criteria based on the access probability, so that the UEs shall be more encouraged to reselect a cell with a higher access probability.

  • An Extreme Learning Machine Architecture Based on Volterra Filtering and PCA

    Li CHEN  Ling YANG  Juan DU  Chao SUN  Shenglei DU  Haipeng XI  

     
    PAPER-Information Network

      Pubricized:
    2017/08/02
      Vol:
    E100-D No:11
      Page(s):
    2690-2701

    Extreme learning machine (ELM) has recently attracted many researchers' interest due to its very fast learning speed, good generalization ability, and ease of implementation. However, it has a linear output layer which may limit the capability of exploring the available information, since higher-order statistics of the signals are not taken into account. To address this, we propose a novel ELM architecture in which the linear output layer is replaced by a Volterra filter structure. Additionally, the principal component analysis (PCA) technique is used to reduce the number of effective signals transmitted to the output layer. This idea not only improves the processing capability of the network, but also preserves the simplicity of the training process. Then we carry out performance evaluation and application analysis for the proposed architecture in the context of supervised classification and unsupervised equalization respectively, and the obtained results either on publicly available datasets or various channels, when compared to those produced by already proposed ELM versions and a state-of-the-art algorithm: support vector machine (SVM), highlight the adequacy and the advantages of the proposed architecture and characterize it as a promising tool to deal with signal processing tasks.

  • Blind Source Separation and Equalization Based on Support Vector Regression for MIMO Systems

    Chao SUN  Ling YANG  Juan DU  Fenggang SUN  Li CHEN  Haipeng XI  Shenglei DU  

     
    PAPER-Fundamental Theories for Communications

      Pubricized:
    2017/08/28
      Vol:
    E101-B No:3
      Page(s):
    698-708

    In this paper, we first propose two batch blind source separation and equalization algorithms based on support vector regression (SVR) for linear time-invariant multiple input multiple output (MIMO) systems. The proposed algorithms combine the conventional cost function of SVR with error functions of classical on-line algorithm for blind equalization: both error functions of constant modulus algorithm (CMA) and radius directed algorithm (RDA) are contained in the penalty term of SVR. To recover all sources simultaneously, the cross-correlations of equalizer outputs are included in the cost functions. Simulation experiments show that the proposed algorithms can recover all sources successfully and compensate channel distortion simultaneously. With the use of iterative re-weighted least square (IRWLS) solution of SVR, the proposed algorithms exhibit low computational complexity. Compared with traditional algorithms, the new algorithms only require fewer samples to achieve convergence and perform a lower residual interference. For multilevel signals, the single algorithms based on constant modulus property usually show a relatively high residual error, then we propose two dual-mode blind source separation and equalization schemes. Between them, the dual-mode scheme based on SVR merely requires fewer samples to achieve convergence and further reduces the residual interference.

  • Collaborative Spectrum Sensing via L1/2 Regularization

    Zhe LIU  Feng LI  WenLei DUAN  

     
    LETTER-Communication Theory and Signals

      Vol:
    E98-A No:1
      Page(s):
    445-449

    This letter studies the problem of cooperative spectrum sensing in wideband cognitive radio networks. Based on the basis expansion model (BEM), the problem of estimation of power spectral density (PSD) is transformed to estimation of BEM coefficients. The sparsity both in frequency domain and space domain is used to construct a sparse estimation structure. The theory of L1/2 regularization is used to solve the compressed sensing problem. Simulation results demonstrate the effectiveness of the proposed method.