【作者】 张伟岗；

【导师】 尚宇；

【作者基本信息】 西安工业大学 ， 通信与信息系统， 2012， 硕士

【摘要】 作为4G的一项核心,MIMO-OFDM已经被越来越多的人所关注,它可以在复杂的无线通信环境中,在不增加频谱带宽和额外的发射功率的前提下,极大的提高无线通信系统的传输速率和可靠性。空时编码技术是实现MIMO-OFDM系统性能的一种有效的方式,本文在对国内相关研究的基础上,主要是围绕着空时编码进行了分析研究。首先,阐述了在现代通信中所面临的困境以及MIMO技术与传统的通信技术相比的巨大优势及其原因,并且对多输入多输出(Multiple Input Multiple Output,MIMO)的天线技术和正交频分复用(Orthogonal Frequency Division Multiplexing, OFDM)技术分别进行了分析研究。其次,在MIMO系统模型建立的基础上介绍了几种常用的空时编码技术,分析、比较了它们的优缺点,针对Alamouti的经典算法做了进一步的研究和拓展,并且对编码后和未编码的OFDM系统仿真结果进行了分析和比较,仿真结果表明,编码后的OFDM系统的可靠性和误码率都得到了很大的改善。然后,针对MIMO技术在宽带情况下受限的问题,将MIMO和OFDM结合了起来。对MIMO-OFDM系统中的空时分组编码和空时频分组编码(Space-time frequency block code, STFBC)技术进行了理论分析,并且与OFDM系统相结合,从误码率的角度进行仿真分析,在误码率为10-2时,编码后的系统相对于STBC-OFDM系统所需信噪比约下降3dB,提高了系统的可靠性。更多还原

【Abstract】 As one of the most important technologies, MIMO-OFDM has attracted a lot of attention. It can enormously improve the data-transmission rate and the reliability in complex environments of wireless communication without increasing the spectrum bandwidth and the transmission power. Space-time code is a way which can implement the performance of the MIMO-OFDM. Some work has been done according to the researches at home and abroad.Firstly, difficulties faced by modern communication and the advantages of MIMO compared with traditional communication technologies have been described. The Multiple Input Multipe Output (MIMO) antenna technology and Orthogonal Frequency Division Multiplexing (OFDM) technology are analysised and researched separately. Secondly, several common code techniques have been introduced based on the established MIMO system. There are some analysis and comparisons between them. To Alamouti classical algorithm research and development, the code and not code of OFDM systems simulation results are analyzed and compared, the simulation results show that the code of the reliability of the system of OFDM after all got the bit error rate and greatly improved. Finally, as the limits of MIMO in the broadband, MIMO and OFDM are combined. After the theoretical analysis of STBC-OFDM and STFBC-OFDM, from the point of view of ber simulation analysis, the bit error rate in 10-2, coding system relative to STBC-OFDM system required signal-to-noise ratio of about 3 dB decline, improve the reliability of system.更多还原