基于DFT的MC-CDMA系统信道估计算法

MC-CDMA Channel Estimation Algorithm Based on DFT

基于导频辅助的最小平方(LS)算法是MC-CDMA中常用的信道估计算法,它运算量低,实现简单,但信道估计精度差。该文讨论了MC-CDMA的导频插入方式,提出一种基于离散傅里叶变换(DFT)的信道估计算法。该算法将LS信道估计循环前缀长度外的时域响应值置零,并设定阈值忽略循环长度内的噪声和无效径响应。该算法保留了LS算法运算量小和实现简单的优点,大大降低了噪声对信道估计精度的影响,仿真结果验证了算法的有效性。

Least square （LS） algorithm based on pilot is a traditional channel estimation algorithm in multi-carrier code division multiple access （MC-CDMA）. LS algorithm has low complexity and is easy to implemented, but the algorithm has poor performance. In order to eliminate the noise during channel estimation, a new channel estimation algorithm based on discrete Fourier transform （DFT） is presented. The algorithm remarkably enhances the channel estimation performance through clearing the time domain response outside the length of cyclic prefix （CP） and ignoring the noise and invalid channel response during the length of CP. The algorithm described in this paper has low complexity and is validated by computer simulation.