《ofdm系统基本原理讨论及发送接收模块实现》-毕业论文.doc

PAGE 毕 业 设 计（论文） 题 目OFDM系统基本原理讨论及发送接收模块 实现 电信学 院 信息 系 17 班 学 生 指导教师 设计所在单位 电信学院信通系  摘 要 正交频分复用OFDM（Orthogonal Frequency Division Multiplexing）技术是一种新兴的移动通信技术。由于其近年来在个人无线通信及多媒体通信方面所表现出来的良好性能，已被广泛的应用于无线局域网、数字音频广播(DAB)、数字视频广播(DVB)系统中。正交频分复用（OFDM）技术将会成为下一代移动通信系统的核心技术。 正交频分复用技术 ,是近年来受到人们广泛关注的一种调制技术, 在高速无线数据传输领域有很大的应用前景。它将高速的数据流分解成许多低速率子数据流，利用相互正交且重叠的多个子载波同时传播，它的主要优点是抗符号间干扰能力强，频带利用率高，能有效地对抗多径衰落。 本文在分析和总结相关文献的基础上，首先介绍了正交频分复用技术的基本原理,并讨论了其中的关键技术,然后运用MATLAB构建OFDM系统, 并加入自适应功率和比特分配算法，通过具有高斯白噪声的频率选择性信道，观察在不同的信噪比条件下，系统的误码率如何变化,从而分析系统在不同调制方式下的性能。 关键词：正交频分复用,BPSK, 16QAM, IFFT ABSTRACT Orthogonal Frequency Division Multiplexing OFDM（Orthogonal Frequency Division Multiplexing） techniques is a new technique used in the mobile communication .Because of its good performances in the field of wireless personal and multimedia communications, it has been used in wireless local network, digital audio broadcasting (DAB)，digital video broadcasting(DVB) systems. Orthogonal Frequency Division Multiplexing (OFDM) techniques will be the core techniques of the next generation mobile communications. OFDM is a modulation technology, which is very popular in recent years, with a good application future in the field of high speed wireless communications. It splits a high-rate data stream into a number of lower-rate data streams that are transmitted simultaneously over a number of subcarriers. The benefits of OFDM are resiliency to inter-symbol interference, high spectral efficiency and efficient to reduce multi-pass interference. Based on related literature, this paper first introduced the basic theory of Orthogonal Frequency Division Multiplexing (OFDM) and discussed the key techniques of OFDM. Then an OFDM simulation system is constructed on MATLAB platform. Furthermore the power and bit load arithmetic is adopted in the simulation. The bit error rate under different SNR is present