基于粒子滤波的OFDM载波频偏和信道联合估计  

Carrier frequency offset and channel joint estimating algorithm for OFDM system base on PF

作　　者：董众 徐卓异[2] 张善从[1] 

机构地区：[1]中国科学院空间应用工程与技术中心,北京100094 [2]北京卫星信息工程研究所,北京100083

出　　处：《现代电子技术》2014年第22期48-51,共4页Modern Electronics Technique

摘　　要：一种基于粒子滤波(PF)的正交频分复用(OFDM)系统在慢衰落瑞利信道下联合信道估计和载波恢复的新方法被提出。该算法适用于多径时变信道模型以及等效离散时间信道模型。算法引入了在非线性系统参数估计和跟踪领域上十分有效的PF方法,将Kaman滤波与序贯蒙特卡罗采样(SMCS)相结合来估计信道衰落系数以及载波频偏(CFO)的后验概率密度,从而通过计算得到信道的响应函数,并在此基础上,利用MMSE均衡器消除码间串扰(ICI),进行码元估计。仿真结果表明了算法的有效性和优越性。A new algorithm of joint carrier recovery and channel estimation for orthogonal frequency-division-multiplexing （OFDM） system based on particle fitering （PF） in slow Rayleigh fading channel is proposed in this paper. The algorithm is suitable for both the multipath time-varying channel model and the equivalent discrete-time channel model. PF method effective for parameter estimation and tracking for non-linear model is introduced into the algorithm. In the algorithm,the channel fading coefficients and the posterior probability density of the unknown carrier frequency offset （CFO） are estimated in combination with Kalman filtering and sequential Monte Carlo sampling. The channel response function is got by computation. Based on this, MMSE equalizer is used to estimate the inter carrier interference（ICI）,so as to perform code element estimation. The simula-tion result indicated effectiveness and superiority of the algorithm.

关 键 词：正交频分复用 信道估计 时延 载波频偏 粒子滤波 

分 类 号：TN951.34[电子电信—信号与信息处理]