摘要： 为提高正交频分复用(OFDM)系统的信道估计精度，根据频谱资源的无线信道特性，提出基于因子图的OFDM系统信道估计算法，包括二维联合信道估计算法和2个级联的一维信道估计算法。将时变频率选择性衰落信道建模为一阶自回归模型，使信道参数之间的交互信息近似为高斯分布，利用和积算法实现OFDM系统的联合信道估计和符号检测。仿真结果表明，该信道估计算法能够以较低的计算复杂度逼近最优的估计性能。
关键词:
正交频分复用,
信道估计,
符号检测,
因子图,
和积算法
Abstract: According to the characteristics of the wireless channel, channel estimation algorithms based on the factor graph are proposed for Orthogonal Frequency Division Multiplexing(OFDM) system to improve the precision of channel estimation and bandwidth efficiency, which include two-dimension joint channel estimation and one-dimensional channel estimation algorithm. Time-varying frequency-selective fading channels can be modeled as one order autoregressive processes and approximating messages as Gaussian distribution, a novel channel estimation and symbol detection method for OFDM system is deduced by applying sum-product algorithm on the factor graph. Simulation results show that the algorithm can achieve good performance with low computational complexity.
Key words:
Orthogonal Frequency Division Multiplexing(OFDM),
channel estimation,
symbol detection,
factor graph,
Sum-product Algorithm(SPA)
中图分类号:
郭艳华, 郭心悦, 徐伯庆. OFDM系统中基于因子图的信道估计算法[J]. 计算机工程, 2013, 39(3): 72-76.
GUO Yan-Hua, GUO Xin-Yue, XU Ba-Qiang. Channel Estimation Algorithm Based on Factor Graph for OFDM System[J]. Computer Engineering, 2013, 39(3): 72-76.