摘要
OFDM系统对相位噪声(PHN)非常敏感,由其引起的子载波相位旋转和载波间干扰(ICI)会严重恶化系统性能。本文提出了一种新的OFDM接收机PHN迭代估计方法,利用优化理论(Majorization)得到最大似然(ML)代价函数的优化函数,通过对优化函数求最大化得到ICI系数的迭代估计,将估计的ICI系数变换到时域得到PHN估计,来校正每个样点的相位误差,从而达到抑制PHN的目的。与传统的基于ML的PHN估计方法相比,该方法具有较低的运算复杂度。文章对算法在多径信道环境下进行了仿真,结果表明所提方法对PHN引起的ICI有较好的估计性能。
One of the main drawbacks of OFDM is its high sensitivity to phase noise （ PHN）, which gives rise to subcarriers phase rotation and intercarrier interference （ICI） for the orthogonality of subcarriers is destroyed. In this paper, a iterative PHN estimator is proposed. ICI coefficients are estimated in frequency domain by maximizing the surrogate function, which is the majorization function of the ML function. Then ,the ICI coefficients are transformed into phase errors in time domain to compensate the phase rotation. The proposed estimator has a lower complexity than the conventional ML estimator. Simulation results are reported in multi-path channel models, which show that the proposed algorithm has superior ICI estimation performance.
出处
《信号处理》
CSCD
北大核心
2009年第3期418-422,共5页
Journal of Signal Processing
基金
国家自然科学基金资助项目(60172078)
关键词
OFDM
相位噪声
载波间干扰
优化函数
迭代
Orthogonal Frequency Division Multiplexing （OFDM）
Phase Noise （PHN）
Intercarrier Interference （ICI）
Majorization function
Iteration
