导　　师： 陈文正

学科专业： 081001

授予学位： 硕士

作　　者： ;

机构地区： 浙江大学

摘　　要： 宽带无线通信的持续高速的需求增长刺激了新的通信技术的不断产生,而这些技术的发展,很大程度上都来自于不同技术的互相补充与融合,这也成为新标准的源泉。正交频分复用/(OFDM/)技术在提供高效的频谱利用率以及良好的抗多径性能的同时,通过多输入输出/(MIMO/)技术来进一步增加信道容量,在不增加信号带宽的基础上取得更高的传输速率和更好的传输质量。因此MIMO-OFDM技术近年来在成为研究热点的同时,已被认为是下一带移动通信和网络接入标准中的核心技术。 本文主要对MIMO-OFDM系统物理层的关键技术进行了研究,并主要对系统的同步和信道估计算法进行了深入的分析,并提出了一些改进。最后进行了MIMO-OFDM基带系统基于FPGA的物理层设计,对其中一些关键模块的设计,比如信道估计和空时译码模块进行了详细的讨论。 第一章绪论部分首先结合宽带无线通信技术发展的历史就MIMO-OFDM技术产生发展的背景进行了分析,指出了MIMO-OFDM研究与发展方向,最后总结了本文的工作目标和基本要求。 第二章主要是推导分析了MIMO-OFDM系统的基本原理,先分别从OFDM技术和MIMO技术两方面概括性的介绍了其理论以及技术特点,最后对MIMO与OFDM结合的关键技术进行了讨论。 第三章是对MIMO-OFDM同步算法的研究,主要针对基于训练序列的同步算法进行了深入讨论,关注点是训练序列的设计。针对原有的一些算法进行了总结与比较,并主要对基于频域设计的训练序列符号同步算法做出了改进。 第四章首先从基于导频的信道估计算法推导开始,关注点放在MIMO-OFDM系统下的自适应信道估计算法研究。文章将原有的一些OFDM自适应信道估计算法扩展到MIMO领域,结合基于共轭梯度的自适应算法并做出了一些改进。 第五章节是本文的硬件设计部分,文章基于一个2发2收MIMO-OFDM系统进行了基带数字处理部分的FPGA设计工作,根据设计要求实现了发送端和接收端数据处理的基本功能,为完善的和更高性能的MIMO-OFDM系统实现奠定了基础。 The keeping growth of the demand for broadband wireless service stimulates the emergence of new communication technology continually, while most of these come from the combination of different existing techniques, which may also becomes the origin of new standards. Orthogonal Frequency Division Multiplexing /(OFDM/) technique increases the spectrume efficiency and is good at combating mutipath fading of the channel, which can still increase the channel capacity without power and bandwidth costs by integrating Mutiple Input and Mutiple Output /(MIMO/) solution. Therefore, MIMO-OFDM has already been in widely research for years and it is considered as the key technique for the next generation mobile communication and broadband wireless network access system. This paper concentrates on the key algorithms of MIMO-OFDM system, containing the analysis and improvement of system synchronization and channel estimation. Then a baseband MIMO-OFDM system design based on FPGA is presented, with focus on the module design to implement the algorithm. In Chapter 1, a brief history introduction of MIMO-OFDM based on the development of broadband wireless communication is presented at first, and then it analyzes the direction of MIMO-OFDM development and gives the main work and contribution of this paper. In Chapter 2, the principle of MIMO-OFDM is analyzed. Firstly, it gives the theory and technique character of OFDM and MIMO separately, the key techniques in combining the MIMO and OFDM is discussed. The research work for MIMO-OFDM synchronization is in Chapter 3. Under the discussion of training sequence synchronization algorithm, it focuses on the training sequence design. The existence algrorithm is compared and summarized, and modification is made for improvement. Chaper 4 gives a study work on the channel estimation algorithm, with special focus on the adaptive channel estimation for MIMO-OFDM. It expands some good OFDM adaptive channel estimation algorithm to MIMO-OFDM system, and new adaptive scheme is presented with algorithm improvement. The last part of this paper is mainly about the hardware implementation. In chapter 5, a 2*2 MIMO-OFDM baseband system is desgined based on FPGA platform. Giving the parameter of the system, it discusses the design and implementation of the digital baseband module in the transceiver.

关 键 词： 信道估计 同步 数字基带

分 类 号： [TN919.3]

领　　域： [电子电信] [电子电信]