摘要
对高速运动环境下多普勒效应引起的大载波频偏引起的载波间干扰进行数学分析,建立带频偏的非时变和时变频偏OFDM动态状态空间模型,提出了基于平方根无迹卡尔曼滤波(square-root unscented Kalman filter,SR-UKF)的频偏估计算法。将非线性状态估计思想引入OFDM频偏估计中,实现了对频偏的有效跟踪和估计。仿真结果表明,在大频偏、高阶调制下,SR-UKF频偏估计算法较自消除算法、最大似然估计算法具有更好的误码率性能;在收敛精度、稳定度和对信噪比敏感度方面,性能较扩展卡尔曼滤波算法均有所提升。
The large carrier frequency offset （CFO） caused by the Doppler effect in high-speed environment degrades the ortho-gonal nature of subcarriers in the OFDM system .The ICI was analyzed using mathematical method and the frequency offset non-linear dynamic state-space model was built .The CFO estimation algorithm based on the square-root UKF was proposed .The nonlinear state estimation theory was brought into the OFDM CFO estimation ,and the tracking ability and the estimation accura-cy were enhanced .The simulation results suggest the SR-UKF gains better BER performance than the ICI self-cancellation and the maximum likelihood method ,and it performs better in terms of the convergence speed ,the accuracy and the stability .
出处
《计算机工程与设计》
CSCD
北大核心
2014年第10期3341-3345,共5页
Computer Engineering and Design
基金
国家自然科学基金项目(61202490)
关键词
正交频分复用
多普勒效应
平方根无迹卡尔曼滤波
频偏估计
orthogonal frequency-division multiplexing
Doppler effect
square-root unscented Kalman filter
frequency offset estimation
