北京邮电大学学报

  • EI核心期刊

北京邮电大学学报 ›› 2007, Vol. 30 ›› Issue (6): 77-80.doi: 10.13190/jbupt.200706.77.029

• 论文 • 上一篇    下一篇

利用序列Monte Carlo的OFDM系统符号定时校正

黄海1, 尹长川1,彭端2,乐光新1   

  1. (1. 北京邮电大学 泛网无线通信教育部重点实验室,北京100876;2. 广东工业大学 实验教学部,广州 510006)
  • 收稿日期:2006-12-17 修回日期:2007-05-29 出版日期:2007-12-31 发布日期:2007-12-31
  • 通讯作者: 黄海

Using Sequential Monte Carlo for Symbol Timing Recovery of OFDM Systems

HUANG Hai1, YIN Chang-chuan1, PENG Duan2, YUE Guang-xin1   


  1. (1. Key Laboratory of Universal Wireless Communications, Ministry of Education, Beijing University of Posts and Telecommunications, Beijing 100876, China; 2. Experiment Center, Guangdong University of Technology , Guangzhou 510006,China)
  • Received:2006-12-17 Revised:2007-05-29 Online:2007-12-31 Published:2007-12-31
  • Contact: HUANG Hai

摘要:

针对非高斯、非线性的正交频分复用(OFDM)系统下的符号同步定时校正,常规的卡尔曼滤波算法不能直接解决非线性非高斯的问题,因而提出一种序列蒙特卡罗(SMC)算法。首先将符号定时偏差以及系统的观测方程建模为动态的系统传递模型;然后用加权的离散随机样本点近似所关注的后验概率密度函数,在频率选择性多径信道估计和跟踪OFDM系统符号定时变化。从仿真结果可以看出,SMC算法在相同信噪比(SNR)下的误比特率(BER)及定时均方误差(MSE)均好于扩展卡尔曼滤波(EKF)。

关键词: 正交频分复用, 符号定时, 序列蒙特卡罗

Abstract:

For the case of symbol timing in nonlinear and non-Gaussian orthogonal frequency division multiplexing (OFDM) systems, it is usually difficult to directly utilize Kalman filter. Thereafter, a feasible structure known as sequential Monte Carlo ( SMC) is brought forward. Estimation and tracking the symbol timing offset in frequency selective multi-paths fading channels based on the application of SMC technique is investigated. The problems of symbol timing offset and system observation function are represented as dynamic state-space models and recursive computation of relevant probability distributions using the concepts of importance sampling and approximation of probability distributions with discrete random measures. The performance of the SMC technique and extend Kalman filter (EKF) are compared in terms of bit error rate (BER) and mean square error (MSE) obtained by simulations and SMC superior outperforms EKF for the considered SNR.

Key words: orthogonal frequency division multiplexing, symbol timing, sequential Monte Carlo

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