中文摘要：

首先给出了正交频分复用（OFDM）技术的概念,详细叙述OFDM技术的基本原理和研究现状,阐述OFDM的关键技术及在4G中的应用,给出了4G的技术规范、技术要求和国内外对4G中关键技术的研究现状。分析表明OFDM技术在不增加带宽的情况下能提高系统容量,是4G移动通信技术中的核心技术。最后给出OFDM在今后的4G移动通信系统中的研究方向。

英文摘要：

The concept of Orthogonal Frequency Division Multiplexing （OFDM） technology is introduced. The basic principle of OFDM technology and the research condition are narrated. The key techniques and the application in 4G of OFDM technology are discussed. Analysis indicates that OFDM technology can enhance the capacity of communication system while maintaining bandwidth,and OFDM is the key technology in the 4G mobile communication system. Research trend of OFDM technology in future is given finally.