一种改进的基于DFT-MMSE的信道估计方法

传统的DFT-LS算法在最小二乘(LS)估计的基础上对循环前缀以外的信道冲击响应置零,在性能优于最小二乘(LS)的同时,降低了估计算法的计算复杂度。理想的最小均方差(MMSE)算法与其相比,计算复杂度大,但是性能优于DFT-LS。本文在传统DFT-MMSE估计算法基础上提出了一种新的方法,针对传统DFT-MMSE算法只对循环前缀以外的信道冲击响应做置零处理的问题,对循环前缀以内的信道冲击响应设定阈值门限,有效滤除部分循环前缀以内的噪声。理论分析与仿真结果表明,本文方法的性能优于传统的DFT-MMSE估计算法,劣于理想情况下的MMSE估计算法;计算复杂度低于传统的DFT-MMSE估计算法和理想情况下的MMSE估计算法。

An Improved Channel Estimation Based on DFT-MMSE

Traditional DFT-LS algorithm sets channel impulse response as zero beyond cyclic prefix on time domain, which can not only attain better performance than LS, but also reduce the computational complexity. Compared with DFT-LS, MMSE has more complexity in computing, but can attain better performance. This paper proposes a new estimation method based on traditional DFT-MMSE, which sets threshold to effectively filter the noise within the cyclic prefix channel impulse response. Both theoretical analysis and simulation results show that the proposed method has better performance than the traditional DFT- MSSE estimation algorithm. Moreover, its computing complexity is lower than traditional DFT- MSSE and ideal MMSE channel estimation.