对抗ICI的增强型载波干涉OFDM

Enhanced CI-OFDM in inter carrier interference cancellation

针对载波干涉正交频分复用(CI-OFDM)系统不能对抗高速移动环境下的Doppler扩展问题,为了进一步提高系统在高速移动环境(例如,300 km/h)下的性能,提出了一种新型的增强型CI-OFDM(ECI-OFDM)技术。通过优化设计CI码,添加频率域的循环前缀和循环后缀,并借鉴自干扰消除算法,得到正负间隔的ECI码,可以有效地对抗Doppler扩展造成的子载波间干扰(ICI)。理论分析及仿真结果表明:与传统的CI-OFDM系统相比,ECI-OFDM可以将系统能够支持的移动速度提高1倍以上。

The standard carrier interferometry orthogonal frequency division multiplexing （CI-OFDM） cannot effectively handle the Doppler spread in high-speed mobile environments. This paper describes an enhanced CI-OFDM （ECI-OFDM） to improve system performance in high-speed mobile environments up to 300 km/h. A cyclic prefix and a self-cancellation scheme are employed in the frequency domain using periodic expanded CI codes to cancel the inter-carrier-interference （ICI） caused by the Doppler spread. Theory analyses and simulations show that the maximum speed supported by the system is nearly double that of the standard system.