标题： 高速移动单输入多输出正交频分复用系统中基于位置的ICI消除压缩信道估计算法 显示英文标题

标题： Compressed Channel Estimation with Position-Based ICI Elimination for High-Mobility SIMO-OFDM Systems

摘要： 正交频分复用（OFDM）被广泛用于提供高速列车系统中可靠且高速率的数据通信。然而，随着列车移动性的增加，导致的大多普勒频移会在OFDM系统中引入载波间干扰（ICI），并极大地降低信道估计的准确性。因此，在高移动性环境下研究可靠的信道估计和ICI抑制方法是必要且重要的。本文考虑了一种典型的高速列车（HST）通信系统，并表明通过利用列车位置信息以及基于常规基扩展模型（BEM）信道模型的稀疏性，可以减轻由大大多普勒频移引起的ICI。接着，我们证明了对于基于复指数BEM（CE-BEM）的信道模型，可以通过完全消除ICI来获得每个接收天线的无ICI导频。之后，我们提出了一种新的导频模式设计算法，以减少系统的相干性，从而提高基于压缩感知（CS）的信道估计精度。所提出的最优导频模式独立于接收天线的数量、多普勒频移、列车位置或列车速度。仿真结果验证了所提出方案在高移动性环境下的性能优势。此外，还表明所提出方案对高移动性具有鲁棒性。 显示英文摘要

摘要： Orthogonal frequency-division multiplexing (OFDM) is widely adopted for providing reliable and high data rate communication in high-speed train systems. However, with the increasing train mobility, the resulting large Doppler shift introduces intercarrier interference (ICI) in OFDM systems and greatly degrades the channel estimation accuracy. Therefore, it is necessary and important to investigate reliable channel estimation and ICI mitigation methods in high-mobility environments. In this paper, we consider a typical HST communication system and show that the ICI caused by the large Doppler shift can be mitigated by exploiting the train position information as well as the sparsity of the conventional basis expansion model (BEM) based channel model. Then, we show that for the complex-exponential BEM (CE-BEM) based channel model, the ICI can be completely eliminated to get the ICI-free pilots at each receive antenna. After that, we propose a new pilot pattern design algorithm to reduce the system coherence and hence can improve the compressed sensing (CS) based channel estimation accuracy. The proposed optimal pilot pattern is independent of the number of receive antennas, the Doppler shifts, the train position, or the train speed. Simulation results confirms the performance merits of the proposed scheme in high-mobility environments. In addition, it is also shown that the proposed scheme is robust to the respect of high mobility.