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1、 硕士学位论文硕士学位论文 OFDM 自适应调制性能研究 OFDM ADAPTIVE MODULATION PERFORMANCE ESTIMATION 马马林林 哈尔滨工业大学 2009 年 12 月 国内图书分类号：TN911.3 学校代码： 10213 国际图书分类号：654 密级：公开 工学硕士学位论文 OFDM 自适应调制性能研究 硕 士 研 究 生 ： 马林 导 师 ： 郭庆教授 申请学 位 ： 工学硕士 学科 ： 信息与通信工程 所 在 单 位 ： 电子与信息工程学院 答 辩 日 期 ： 2009 年 12 月 授予学位单位 ： 哈尔滨工业大学 哈尔滨工业大学工学硕士学位论文 -
2、 - 2Classified Index: TN911.3 U.D.C: 654 Dissertation for the Masters Degree in Engineering OFDM ADAPTIVE MODULATION PERFORMANCE ESTIMATION Candidate： Osamah Mohammed Al-Marrani Supervisor： Prof. Guo Qing Academic Degree Applied for： Master of Engineering Speciality： Information and Communication En
3、gineering Affiliation： School of Electronics and Information Engineering Date of Defence： December, 2009 Degree-Conferring-Institution： Harbin Institute of Technology Dissertation for Master Degree in Engineering, Harbin Institute of Technology I 摘摘 要要 WiMAX 由 IEEE 组织提出，其标准被指定为 802.16d-2004(应用于固定无线
4、环境)和 802.16e-2005(移动无线环境)，旨在提供全球互通的微波接入。目前， 电信行业高度关注能够进行点到多点、利用多种传输模式实现数据无线传输的 技术。WiMAX 包含全移动 Internet 接入。到目前为止，利用 WiMAX 已经实 现了多种应用，例如作为发展中国家 3G 移动系统的替代，无线数字用户线 WDSL 以及无线本地环路 WLL。本文估计了 WiMAX OFDM 物理层的不同调 制方式例如 BPSK，QPSK 和 QAM（16 和 64）的性能，并“利用循环前缀，在 发送端加上冗余比特来减小符号间干扰，改善比特误码率”，从而得到 WiMAX 物理层的最佳性能。在基于“
5、有循环前缀和无循环前缀”两个 OFDM 模型的整个 仿真过程中，我们使用加性高斯白噪声信道，考虑瑞利衰落，且前向纠错信道 编码为码速率的卷积编码，并使用 FFT 和 IFFT 以及自适应调制等技术。通 过 MATLAB 仿真，使用比特误码率 BER、信噪比 SNR 和错误概率 Pe 来评价 系统性能。 关键词：关键词：自适应调制；循环前缀；比特误码率；信噪比；错误概率。Dissertation for Master Degree in Engineering, Harbin Institute of Technology II Abstract WiMAX is introduced by t
6、he Institute of Electrical and Electronic Engineers (IEEE) which is standard designated 802.16d-2004 (used in fixed wireless applications) and 802.16e-2005 (mobile wireless) to provide a worldwide interoperability for microwave access. At present, telecommunication industries are highly concerned wi
7、th the wireless transmission of data which can use various transmission modes, from point- to-multipoint links. It contains full mobile internet access. Various applications have already been applied so far using WiMAX, as alternative to 3G mobile systems in developing countries, Wireless Digital Su
8、bscriber Line (WDSL), Wireless Local Loop (WLL). In this thesis work, we estimate the performance for different modulation techniques based on WiMAX OFDM-PHY such as BPSK, QPSK and QAM (Both 16 and 64) “using the cyclic prefix that adds additional bits at the transmitter end in order to reduce inter
9、 symbol interference, to improve bit error rate” to find out the best performance of physical layer for WiMAX. The noise channel AWGN, Rayleigh fading, with Convolution encode with rated code in FEC channel coding, FFT and IFFT, and the Adaptive modulation is used for the whole simulation procedure
10、obtained in two OFDM models “with and without CP”. The performance has been concluded based on Bit Error Rate “BER”, Signal to noise ratio “SNR” and Probability of Error “Pe” output through MATLAB Simulation. Keywords: Adaptive Modulation; Cyclic Prefix; BER; SNR; Pe.Dissertation for Master Degree i
11、n Engineering, Harbin Institute of Technology III Contents Abstract (chinese) . I Abstract . II Chapter 1 Introduction . 1 1.1 Why WiMAX . 1 1.2 Background on IEEE 802.16 . 1 1.3 Different between Fixed it is a single base station in shape of a box with a wired connection to the Internet, such as a
12、DSL, cable, or T1 line. It can broadcasts to multiple users over distances of 100 meters indoor and 400 meters outdoor 36On the contrary WiMAX is a high-speed wireless packet-based radio connectivity for metropolitan area wireless standard that provides wireless broadband connections similar to Wi-F
13、i but with much coverage of up to 50 kilometers in LOS and 10 kilometers in NLOS condition. . 2.6 IEEE 802.16 Protocol layers IEEE 802.16 standard WiMAX gives freedom in several things compared to other technologies. The focus is not only on transmitting tens of megabits of data to many Dissertation
14、 for Master Degree in Engineering, Harbin Institute of Technology - 17 - miles distances but also maintaining effective QoS (Quality of Services) and security. This section gives an overview of IEEE 802.16 protocol layers and OFDM features. WiMAX 802.16 is mainly based on the physical and data link layer in OSI reference model. Here, Physical layer can be single-carrier or multi-carrier (PHY) based and its data link layer is subdivided into two layers 1. Logical Link Control (LLC) 2. Medium Access Control (MAC) MAC is furt
