OFDM系统中基于导频的低秩信道估计方法

主要研究了正交频分复用(OFDM)系统中基于导频辅助的低秩信道估计方法,提出了一种秩的取值及自适应秩跟踪方法。低秩估计方法利用信道的频域(和/或时域)相关性以及奇异值分解技术。其中关键的秩估计也就是信号子空间的维数判定必须在计算复杂度和估计误差两方面折中考虑。仿真表明给出的秩估计方法能够比较准确地反映出信号子空间的大小,大大降低运算复杂度。在此基础上的低秩方法与线性最小均方误差(LMMSE)估计的性能几乎一样并且对子载波总数的大小和信道环境变化的敏感性相当小,通过分块估计还可以进一步降低运算量。

Pilot-aided low-rank channel estimation methods for OFDM systems

It was talking about the pilot-aided low-rank channel estimation method in orthogonal frequency division multiplexed (OFDM) systems. Low-rank estimation used the frequency correlation of the channel and singular value decomposition method. The key problem, rank estimation, was a tradeoff between complexity and approximation error. The range of the rank and an adaptive rank approximation method were presented. Simulation results show that when appropriate rank estimation is obtained low-rank estimation performs almost the same as LMMS estimator and it is also insensitive to the number of sub-carriers and channel variations. More complexity reduction can be achieved by partitioning all tones into subsystems.