论文标题
压缩通道估计，基于位置的ICI消除高速公路SIMO-OFDM系统
Compressed Channel Estimation with Position-Based ICI Elimination for High-Mobility SIMO-OFDM Systems
论文作者
论文摘要
正交频划分多路复用（OFDM）被广泛用于在高速火车系统中提供可靠和高数据速率通信。但是，随着列车迁移率的增加，最终的大型多普勒移位引入了OFDM系统中的载波干扰（ICI），并极大地降低了通道估计的精度。因此，在高弹性环境中研究可靠的通道估计和ICI缓解方法是必要和重要的。在本文中，我们考虑了一个典型的HST通信系统，并表明可以通过利用火车位置信息以及基于常规基础扩展模型（BEM）基于的频道模型来减轻大型多普勒转移引起的ICI。然后，我们表明，对于基于复杂的指数BEM（CE-BEM）的通道模型，可以完全消除ICI，以在每个接收天线处获得无ICI的飞行员。之后，我们提出了一种新的试点模式设计算法，以降低系统的连贯性，因此可以提高基于压缩的传感（CS）频道估计精度。提出的最佳试点模式与接收天线的数量，多普勒偏移，火车位置或火车速度无关。仿真结果证实了在高动作环境中所提出的方案的性能。另外，还表明所提出的方案对高迁移率的尊重是可靠的。
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.
