基于无迹卡尔曼滤波的双选信道估计方法

A doubly-selected channel estimation method based on an unscented Kalman filter

针对高速移动场景中由于信道存在时频域选择性衰落(双选衰落)导致正交频分复用(orthogonal frequency division multiplexing,OFDM)通信系统受到子载波间干扰而使通信质量下降的问题,采用基扩展信道模型,在消除子载波间干扰(inter carrier interference,ICI)影响的同时节约信道估计算法的空间复杂度。针对基扩展模型(basis expansion model,BEM)下的非线性信道状态空间模型,采用无迹卡尔曼滤波(unscented Kalman filter,UKF)方法进一步跟踪信道响应提升信道估计精度。仿真分析表明,本研究所提方法能够有效提升信道估计的精度,相对于传统算法具有更好的误码率性能和鲁棒性。

Due to selective fading in time domain and frequency domain(doubly-selective fading) causes the inter carrier interference(ICI) in the orthogonal frequency division multiplexing(OFDM) system, the communication quality would be declined in high speed environment. The basis expansion model(BEM) decreased the spatial complexity of the channel estimation algorithm while eliminating the ICI impact effectively. For the non-linear channel state space model under the BEM, the unscented Kalman filter(UKF) was adopted to track the channel response in time and improve channel estimation accuracy. Simulation results showed that the BEM-UKF was able to effectively improve the accuracy of channel estimation and had better bit error rate(BER) performance and robustness than traditional algorithms.