超高速移动OFDM系统频偏估计与信道估计

发布时间：2018-06-06 05:30

本文选题：超高速移动通信 + 正交频分复用系统　；参考：《合肥工业大学》2014年硕士论文

【摘要】：正交频分复用(OFDM)技术因其抗衰落能力强、频谱利用率高等优点,在移动通信中有着广泛的应用。然而在空空通信等超高速移动环境下,OFDM系统对超高速移动引起的时变多普勒频偏敏感,需要对传统的OFDM系统的频偏估计和信道估计技术进行研究以适应超高速移动通信环境。本文分析了超高速移动环境下的无线信道特性和OFDM系统频偏估计、信道估计技术。在此基础上,针对超高速移动环境的特殊应用背景,深入开展了OFDM系统的频偏估计和信道估计的研究工作,本文工作的主要贡献如下：1.在研究了超高速OFDM系统传输模型和信号结构的基础上,提出了一种基于循环前缀的频偏实时估计算法,并分析了多径传输对于循环前缀数据的“污染”效应,对该算法进行了优化,提高了算法的频偏估计性能。2.根据超高速移动OFDM系统的频偏信息时变性的特点,分析了传统的基于接收端时域频偏补偿方式实时性较差的缺点,设计了一种全新的实时性较好的时频联合频偏补偿方案。3.针对本文的时频联合的频偏补偿方案,优化了传统的信道估计算法,使得信道估计包含实时频偏信息,验证了优化后算法的估计性能。通过上述研究本文设计了超高速OFDM系统具有频偏估计、频偏补偿、信道估计的新的传输模型。试验结果表明：本文的传输模型不仅能实时地估计多普勒效应产生的频偏,而且具有较好的信道估计性能,在高速和超高速移动通信系统设计中具有较大的应用价值。
[Abstract]:Orthogonal Frequency Division Multiplexing (OFDM) technology has been widely used in mobile communication due to its strong anti-fading ability and high spectral efficiency. However, in ultra-high speed mobile environments such as air-to-air communication, OFDM systems are sensitive to time-varying Doppler frequency offset caused by ultra-high speed movement, so it is necessary to study the frequency offset estimation and channel estimation techniques of traditional OFDM systems to adapt to ultra-high speed mobile communication environment. In this paper, the characteristics of wireless channel and the frequency offset estimation and channel estimation technology of OFDM system are analyzed. On this basis, in view of the special application background of ultra-high-speed mobile environment, the frequency offset estimation and channel estimation of OFDM system are deeply studied. The main contributions of this paper are as follows: 1. On the basis of studying the transmission model and signal structure of ultra-high speed OFDM system, a real-time frequency offset estimation algorithm based on cyclic prefix is proposed, and the "pollution" effect of multipath transmission on cyclic prefix data is analyzed. The algorithm is optimized to improve the performance of frequency offset estimation. 2. 2. According to the characteristics of time-varying frequency offset information in ultra-high speed mobile OFDM system, the shortcoming of traditional time-domain frequency offset compensation method based on receiver is analyzed, and a new time-frequency joint frequency offset compensation scheme .3. is designed. For the time-frequency joint frequency offset compensation scheme in this paper, the traditional channel estimation algorithm is optimized, which makes the channel estimation contain real-time frequency offset information, which verifies the performance of the optimized algorithm. In this paper, a new transmission model of ultra-high speed OFDM system with frequency offset estimation, frequency offset compensation and channel estimation is designed. The experimental results show that the proposed transmission model not only can estimate the frequency offset of Doppler effect in real time, but also has better channel estimation performance. It has great application value in the design of high-speed and ultra-high speed mobile communication systems.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.53

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