MC-CDMA系统基于子空间跟踪的导频辅助信道估计

基于导频辅助的MC-CDMA系统信道估计方法通过在确定的时频位置发送已知的导频符号来获取信道参数,通常包括导频位置的最小二乘估计和内插滤波两步。为了提高导频位置信道频域特性的估计精度,使得后续内插滤波的精度相应得到提高,本文利用基于Givens旋转的子空间跟踪方法构成了对信道的时变参数的估计和跟踪,得到了较为准确导频信道估计。仿真表明,我们给出的基于子空间跟踪的信道估计方法具有更好的稳定性和更高的估计精度。

Pilot-assisted Channel Estimation in MC-CDMA Based on Subspace Tracking

Channel parameters in MC-CDMA systems over fading channels are generally obtained by transmitting pilot symbols in given positions of the time-frequency grid. The pilot-based method usually involves the Least Square estimation step on the pilot subcarriers and the interpolation step over the entire time-frequency grid. Increasing the accuracy of the pilot estimation will accordingly increase the precision in the interpolation step. We propose in this paper a delay-subspace tracking algorithm based on Givens rotation. Performed on parameterized model of the channel, simulations prove that our channel estimation is more robust and accurate.