双选信道下SC-FDE系统中改进的信道估计方法

Modified Channel Estimation Method in SC-FDE System over Doubly Selective Channel

为更好地恢复双选信道下单载波频域均衡(SC-FDE)系统中的发送信息,利用该系统特有的帧结构,提出一种简单的改进算法以提高信道估计性能。新算法将两个相邻数据块的导频组成一个新导频,再根据循环卷积的时域循环移位性质对新导频进行处理,得到若干组不同移位时的信道系数估值,最后利用无线信道的稀疏特性,对每组信道估值进行降噪处理并求平均得到最终的信道估值,进而改善了信道估计性能和频域均衡效果。

This paper proposes a modified method to improve the channel estimation performance,in order to effectively recover the transmitted information in SC-FDE system over doubly-selective channel.Firstly,the special frame structure in this system is considered and the pilots of two adjacent data blocks are combined to acquire a new pilot.Then based on the cyclic shift properties in time domain of circular convolution,the new pilot is used to derive several channel coefficients under different shift evaluation.Finally,the sparse characteristics of wireless channel are considered,and the disturbance of the noise is eliminated for the estimation of each group of the channel coefficients,and the estimation results are averaged,so that the performance of the channel estimation and the frequency equalization is greatly improved.