多输入多输出系统的关键技术研究

【作者】 张雯；

【导师】 李宏；

【作者基本信息】 西北工业大学 ， 电路与系统， 2006， 硕士

【摘要】 新一代移动通信系统需要提供极高的数据速率,由于可用无线频谱资源的有限性,高数据速率只能通过提高频谱利用率来实现。多输入多输出(Multiple-Input-Multiple-Output:MIMO)系统在发射端和接收端分别采用多个发射天线和接收天线,通过研究表明,多输入多输出技术是无线移动通信领域的重大突破,它能够在不增加带宽的情况下成倍地提高通信系统的容量和频谱利用率,被认为是新一代移动通信系统必须采用的关键技术之一。 本文首先分析了无线信道的特点,并建立了多输入多输出系统的信道模型。在此基础上对MIMO系统的信道容量进行了分析讨论,并对几种典型系统(SISO、MISO、SIMO、MIMO)的信道容量进行了计算机仿真,比较了这几种系统之间信道容量的差异。深入研究了瑞利相关衰落条件下MIMO系统的信道容量,讨论了相关衰落对信道容量的影响,将注水算法应用于相关衰落的MIMO系统的信道容量分析中,给出了其仿真分析结果。在MIMO信道中,空时编码是可以使信道容量接近理论容量的一种编码,而空时分组码是得到广泛应用的一种空时编码技术。本文在分析Almouti发射分集方案的基础上,研究了正交空时分组码的编码和译码算法,运用一种简化的译码算法给出了正交空时分组码的性能仿真结果,并对其误码性能进行了讨论和分析。更多还原

【Abstract】 With the development of a communication technology, it is desired the mobile communication systems which can support very high rate data transmission. Because available radio spectrum is limited, higher data rates can be achieved only by enhancing spectral efficiency. MIMO(Multiple-Input-Multiple-Output) system adopts several antennas transmitting and receiving. The analysis indicates that MIMO technology is the important progress in wireless communications. It can enhance the capacity and spectral utilization efficiency of communication systems while no the increase of channel bandwidth. MIMO is one of the key technologies in the next generation mobile communication systems.In this dissertation, the author firstly analyzes the characteristic of the wireless channel, and establishes the channel model of the MIMO system. On the basis of it, the capacity of MIMO channel is discussed, the capacity of several typical systems is simulated, such as SISO, MISO, SIMO and MIMO, the difference among those are compared with each other. The key points are focused on the capacity of MIMO channel with Rayleigh Correlated Fading, and the effects of fading correlation on capacity of MIMO channel. Then, the capacity of MIMO channel with Rayleigh Correlated Fading is simulated by using water-pouring algorithm. Space-time coding is a set of practical signal design technique which is aimed at approaching the information theoretic capacity limit of MIMO channels. Therefore, in this article,we analyze the Alamouti’s transmit diversity technique, do some research on the encoding and decoding algorithms of orthogonal space-time block coding, and present the simulation result of STBC utilizing a simple decoding algorithm. Finally, the performance of orthogonal space time block coding is evaluated by computer simulations.更多还原