移动OFDM系统中的ICI消除算法研究

Study on ICI Cancellation Algorithms for Mobile OFDM Systems

在宽带OFDM系统中,高速移动引起的多普勒效应导致载波间干扰(InterCarrier Interference,ICI)。该文在充分利用ICI分布特性的基础上,使用部分信道信息推导出两种新的低复杂度MMSE和DFE均衡算法。分析及仿真表明,新算法能够灵活可控地实现接收机性能与复杂度的有效折衷。在计算开销近似相同的条件下,提出的DFE均衡方案有效消除了传统接收机差错性能的"地板效应"(error floor),从而获得了性能改善。

For broadband OFDM systems, Doppler effect induced by high mobility gives rise to the InterCarrier Interference （ICI）. By fully exploiting the ICI distribution property and partial channel information, two novel complexity-reduced Minimum Mean Square Error （MMSE） and Decision-Feedback Equalizer （DFE） are derived. Theoretical analysis and simulations illustrate that the new schemes provide a flexible and controllable approach to obtain the tradeoff between performance and complexity. When compared with existing schemes, the proposed DFE equalizer mitigates the ＂error floor＂ effect at the classical receiver and obtains performance improvement with the same computational overheads.