移动通信中OFDM技术的研究

【作者】 谢强；

【导师】 洪嘉祥；

【作者基本信息】 南京理工大学 ， 电磁场与微波技术， 2002， 硕士

【摘要】 本文主要研究正交频分复用(OFDM)及其抗多径衰落的一些技术，并利用计算机进行仿真。在对移动信道进行详细的理论分析和研究的基础上，首先给出了OFDM的基本原理，并简要介绍了克服多径衰落的一些措施。然后具体讨论了OFDM的几种关键技术：1．信道编码与OFDM的结合(COFDM)，增强系统进一步提高消除多径影响的能力；2．分集技术，重点介绍了一种空间频率联合分集接收技术，它能够大幅度降低计算量；3．比特与信道的自适应分配法，是一种有效的动态分配方法。利用Systemview软件进行模拟多径信道下OFDM系统性能仿真，并探讨了仿真过程中的一些问题，最后搭建了OFDM基带仿真系统，并利用TMS320C54DSP芯片，进行了OFDM硬件嵌入式仿真。更多还原

【Abstract】 This paper concentrates on the orthogonal frequency division multiplexing(OFDM) technique and some techniques to resist multipath fading. It also simulates by computer. Based on detailed theoretical analysis and research of the mobile channel, Firstly it introduces the basis principle of OFDM and concisely present some measures to overcome multipath fading, and then discusses several key techniques of OFDM concretely: 1. OFDM combined with channel coding(COFDM) can enhance the ability to lower the effect of multipath fading. 2. A joint frequency and space diversity scheme is presented which can reduce computational cost. 3. An adaptive bit, power and subcarrier allocation is presented. When the channel changes rapidly, this proposed dynamic algorithm is efficient. Other than above, this paper also studies the character of OFDM under multipath fading and gives the baseband computer simulation by Systemview. At last, it performs OFDM DSP hardware plug-in simulation.更多还原