高移动环境下利用无线信号空域特征实现OFDM系统的ICI消除

高移动性正交频分复用(OFDM)系统受多普勒扩展影响产生严重的子载波间干扰(ICI)。根据实际场景中无线信号的空域传播特征，采用WINNER II信道模型建模无线信道，提出利用阵列天线作为接收天线从空域角度消除ICI。该方法利用波达方向估计和波束形成网络对接收信号进行分离，并对分离后的各路信号分别做多普勒频偏补偿，最后将各路处理后的信号进行最大比合并获得多波束分集增益。仿真结果表明，所提方法可有效减小ICI和误码率平台，较处理前可获得5~7 dB的信干比增益。

Inter-carrier interference cancellation using spatial characteristics for high-mobility OFDM communication systems

High-mobility orthogonal frequency division multiplexing(OFDM) systems suffered severe inter-carrier interference(ICI) from Doppler spreading. On the basis of the characteristics of wireless propagation in practical scenarios, a method which employed the WINNER II channel model to represent the practical wireless channel and an antenna array as the receiver to eliminate ICI in space-domain was proposed. The direction of arrival estimation algorithm and the beamforming network were used to separate the received signals in space-domain. Multi-beam diversity gain was obtained finally by means of combining the signals which have been compensated for Doppler frequency shifts(DFS) respectively. Simulation results demonstrate that the proposed method not only effectively reduces ICI and the error floors, but also obtains a 5~7 dB sig-nal-to-interference gain over systems without use of the proposed method.