一种部分信道状态信息下提高频谱效率的方法

A Novel Method to Achieve Average Spectral Efficiency with Imperfect CSI

在已知精确信道状态信息的情况下,使用自适应调制等技术能改善OFDM系统的性能。然而,反馈信息传输延时导致的信道估计噪声和多普勒频移,使得实际的时变快衰落信道条件中不可能获得完全精确的信道状态信息。本文利用多个"过期的"信道估计值,使用扩展自相似过程模型来修正当前的信道估计值。仿真分析表明,在快衰落信道条件下,新方法能有效地改善自适应OFDM系统平均频谱效率。

Accurate channel state information （CSI） is required at the transmitter to achieve the benefits for adaptive OFDM system. But imperfect CSI arises from both noisy channel estimates and Doppler shift in rapidly fading channels, which may also he outdated due to a delay in getting the CSI to the transmitter. The use of multiple estimates is then proposed to improve the performance based on extended self-similar process, which enables the system to achieve average spectral efficiency of rapidly fading channels significantly.