MC-CDMA系统中基于DFT的信道估计改进算法研究

LS信道估计算法运算量小，实现简单，但估计值对噪声影响敏感，算法精度低。为降低噪声对精度的影响，文章提出一种新的基于DFT的LS信道估计改进算法。该算法利用并行PN序列信号特性，通过时延点信息获取算法得到多径信道的时延点信息，并在改进的信道估计算法中利用此信息，最大程度地抑制噪声。仿真结果表明，与现有的基于DFT的LS改进算法相比，本算法可进一步提高估计精度，在低信噪比条件下性能更好。

Improved MC-CDMA System Channel Estimation Algorithm based on DFT

LS channel estimation algorithm has low computation complexity and is easy in implementation, and however, but the result is sensitive to the influence of channel noise, thus the performance is poor. This paper describes a new improved LS algorithm based on DFT, which could reduce the influence of noise to the accuracy of the algorithm. The algorithm makes use of the character of parallel PN signals, acquires channel information by the delay points information getting algorithm and uses it to suppress the noise to maximum. The computer simulation indicates that, Compared with the existing improved LS algorithms based on DFT, the algorithm raises the estimation accuracy and its performance is even better when the SNR is low.