时变衰落信道下的正交频分复用通信系统ICI消除

ICI Cancellation for OFDM Systems in Time-varying Fading Channels

信道的时间变化使得正交频分复用通信系统(OFDM)载波间的正交性遭到破坏,从而产生载波间的相互干扰(ICI),导致系统接收性能明显降低。为解决这个问题,需对接收信号进行ICI消除,以恢复载波间的正交性。传统的ICI分析均在频域进行,在此基础上提出的ICI消除算法存在计算量大或频谱利用率低等缺点。为此,该文对ICI的产生机理和性质进行了时域和频域两方面的分析,在此基础上提出了一种高效ICI消除算法,即时域迭代消除法。理论分析和计算机仿真结果表明:该算法具有消除效果好、计算量小和频谱利用率高等优点。

Time variations of time-varying c hannels lead to the loss of orthogonality among subcarriers,resulting in interc arrier interference(ICI )in orthogonal frequency division multiplexing(OFDM) systems ,and leading to the degrad-ation of system performance.An ICI cancel lation is usually used in the receiver to mitigate ICI and recover the orthogon ality.But the existing ICI analysis approaches are all performed in frequency domain,and the resulted ICI cancellation methods are computationally complex or at the price of sacrificing bandwidth.This paper provides an ICI analysis i n frequency -and time -domain.Based on this analysis,the paper proposes an e fficient time -domain ICI mitigation method.Theoretical analysis and simulat ion results indicate that the proposed method can effectively mitigate ICI and has the advantages of low complexity and high bandwidth efficiency.