分数阶傅立叶变换OFDM系统自适应均衡算法  

The Adaptive Equalization Algorithm for OFDM System Based on the Fractional Fourier Transform

作　　者：陈恩庆[1] 陶然[1] 张卫强[1] 赵娟[1] 孟祥意[1] 

机构地区：[1]北京理工大学电子工程系

出　　处：《电子学报》2007年第9期1728-1733,共6页Acta Electronica Sinica

基　　金：国家自然科学基金项目(No.60572094);国家部委基金项目(No.6140445)

摘　　要：由于子载波间干扰(ICI)的影响,传统OFDM系统均衡方法在快速衰落的信道环境下性能有较大下降.本文提出了一种基于分数阶傅立叶变换的OFDM系统自适应均衡方法,它用分数阶傅立叶变换代替傅立叶变换进行子载波调制与解调,同时在分数阶傅立叶域对接收信号进行自适应均衡.文中给出了最优分数阶傅立叶变换阶次的选取方法,和分数阶傅立叶域最小均方算法的步骤.分析和数值仿真结果表明,最优分数阶傅立叶域的自适应均衡算法较传统频域方法有更好的均衡效果,并且复杂度不高.The performance of equalization in traditional OFDM system is greatly degraded in fast fading channel due to the intercarrier interference （ICI）. This paper proposes an adaptive equalization algorithm for OFDM system based on fractional Fourier transform. In this method, the traditional Fourier transform is replaced by fractional Fourier transform to modulate and demodulate the symbols, and the received signals are equalized adaptively in the fractional Fourier domain. The algorithm for selecting the optimal order of fractional Fourier transform is given in this paper. Moreover, the adaptive equalization algorithm in fractional Fourier domain is derived. Theoretical analysis and numerical simulation results show that the proposed equalizer in optimal fractional Fourier domain can significantly improve the performance of OFDM system compared with Fourier domain equalizer.

关 键 词：分数阶傅立叶变换 正交频分复用 自适应均衡 

分 类 号：TN919[电子电信—通信与信息系统]