【作者】 赵晓红；

【导师】 芦鹏飞；

【作者基本信息】 北京邮电大学 ， 电子与通信工程（专业学位）， 2013， 硕士

【摘要】 近些年来移动通信取得了迅猛的发展,对于更高的信息传输速率的需求在不断增加,基于OFDM(正交频分复用)技术和MIMO(多输入多输出)技术的宽带无线移动通信系统能够利用有限的频谱资源来提供高速可靠的宽带数据业务,成为了当前的研究热点。因为信道估计的精度会直接影响整个通信系统的性能,所以在接收机端信道估计是很重要的一个环节。对于MIMO-OFDM系统来说,经过不同信道之后的多个发射天线信号叠加得到了接收信号,因此相对于SISO-MIMO通信系统来说,信道估计也变得愈加的复杂。因此信道估计成为MIMO-OFDM系统的关键技术之一。本论文的研究工作主要涉及两个方面,包括宽带无线移动通信系统中的信道建模以及信道估计,其中信道估计作为研究重点。首先论文分别对MIMO技术和OFDM技术进行了阐述,从各种方面对两种技术的特点和优点进行了讨论,之后逐步开始介绍信道模型及信道估计算法相关的研究。当接收终端快速移动时,无线MIMO-OFDM通信信道会出现快速时变特性,从而导致子载波问的正交性遭到破坏,引起子载波间干扰,降低系统性能。本论文中首先对时不变的信道进行了分析,然后针对时变无线信道建立了一个基扩展模型,该模型近似于时变信道。然后利用基于导频的时域信道估计方法进行信道估计。在这个模型的基础上,应用导频序列对时变的MIMO-OFDM信道进行估计。更多还原

【Abstract】 In recent years, the mobile communication has been developed rapidly, therefore demand on higher information transmission rate are increasing gradually. Based on the orthogonal frequency division multiplexing (OFMD) and multiple input multiple output (MIMO) technology, broadband wireless mobile communication system will be able to provide high-speed reliable broadband data services using the limited frequency resource. This has become the research hot spot now. Since accuracy of channel estimating will have a direct affect on the performance of the whole communication system, in the receiver side the channel estimation is a very important part. For MIMO-OFDM system, received signal can be gotten by adding several transmitting antenna signals from different channels, so relative to the SISO-MIMO communication system, channel estimation is also becoming more complex. Therefore, channel estimation becomes a key technology for MIMO-OFDM system.Research work in this thesis is involved in channel modeling and channel estimation in broadband wireless mobile communication system, the channel estimation is especially regarded as the research key. First of all, there are some introduction for MIMO and OFDM technology, the characteristics and advantages of these two technologies were discussed from various aspects. Then gradually began to introduce the channel model and channel estimation algorithm related in the research.When the receiving terminal moves fast, wireless MIMO-OFDM communication channel will have fast time-varying characteristics. This will destroy the orthogonality among different subcarriers and will cause Inter-Carrier Interference (ICI), in that case, the system performance will be reduced. This paper analyzed the invariant channel, then on the base of time-varying channel, established several sequence based expansion model, after that, estimated the time domain channel using the pilot in frequency domain. Based on this model, paper estimated time-varying MIMO-OFDM channel using frequency sequence.更多还原