【作者】 李永华；

【导师】 吴伟陵；

【作者基本信息】 北京邮电大学 ， 信号与信息处理， 2007， 博士

【摘要】 无线通信中的MIMO(Multiple Input Multiple Output)技术能够为通信系统带来信道容量的增益，因而作为提高数据传输速率的重要手段而备受关注。然而，空时相关性的存在，使得MIMO通信系统的实际应用受到限制，本文通过分析MIMO系统的信道模型，深入研究空时相关多天线通信系统的有效性，主要工作如下：首先，在深入研究MIMO信道模型的基础上，提出了基于等效簇的MIMO信道几何模型，并对相关系数进行了推导。进而研究了平坦Rician衰落MIMO相关信道下的信道容量，从理论分析和仿真两方面分析了不同参数对遍历信道容量和中断容量的影响。其次，给出了基于等效簇的频率选择性Rician衰落MIMO信道模型，推导了出收发相关的场景下，MIMO-OFDM系统的信道容量表达式；研究了频率选择性Rician衰落MIMO信道容量及物理参数的影响；分析了多簇平坦衰落信道与多径频率选择性衰落信道之间的关系，得出了空时对偶性的结论。再次，验证了基于等效簇平坦衰落模型下Rician衰落MIMO信道容量的界，并分析不同应用场景和不同条件下MIMO信道遍历容量的界。研究了Rician相关衰落MIMO信道互信息的分布，进而对中断信道容量进行分析。重点研究了MIMO-OFDM系统相关衰落信道容量的上下界，推导并证明了收发相关频率选择性Rayleigh衰落的上下界。对频率选择性信道的中断信道容量进行分析，推导出频率选择性衰落系统互信息近似服从高斯分布的方差，并通过仿真验证。最后，研究了反馈MIMO信息论及空时线性预编码系统中的信道容量问题，并与传统的MIMO系统进行了比较。提出了虚拟MIMO预编码技术，并针对未来的多媒体应用，给出了基于QoS的虚拟空时线性预编码系统的功率分配方案。更多还原

【Abstract】 Multiple Input Multiple Output(MIMO) system can offer large gains in capacity for wireless communication system. Therefore, as a means of higher transmission data rate, it has received considerable attention. However, the application of MIMO system is confined for the spatial and temporal correlation. The thesis concerns the validity of MIMO system with spatial and temporal correlation via analyzing the MIMO channel model. The main contribution is described as follows:Firstly, on the basis of investigating the MIMO channel model, we propose an effective cluster-based geometric model for MIMO channel, and deduce the spatial and temporal correlation coefficient. Then, the correlated capacity of flat Rician fading channel is analyzed. The effect of different parameters on the ergodic and outage capacity is performed by theoretic analysis and simulations.Secondly, with effective clusters, a geometric MIMO channel model for frequency-selective Rician fading is presented. The capacity of the MIMO-OFDM system is derived from this model with double correlation scenarios. The effect of different parameters on the frequency-selective capacity is investigated. The relation between multiple clusters in flat fading and multiple taps in frequency-selective channel is analyzed, and conclude that the two is spatial and temporal duality.Thirdly, according to the flat Rician fading model we have proposed, the capacity bounds are validated, and the bounds of ergodic capacity are analyzed on the different conditions and scenarios. The distribution of the mutual information is investigated on the doubly correlated Rician fading channel, and the outage capacity is analyzed. The capacity bounds of MIMO-OFDM system are investigated in correlated fading channels. The bounds of frequency-selective Rayleigh fading are deduced and proved. The outage capacity of MIMO-OFDM system is analyzed. Assuming the mutual information is approximately Gaussian distributed, the variance is derived for the correlated frequency-selective Rician channels. With the channel model, we demonstrate that the approximation is accurate over a range of system parameters.Finally, MIMO information theory with feedback is discussed. The capacity of spatial-temprol linear precoder is compared with that of the traditional MIMO system. Aiming at the multimedia application, a virtual MIMO technology is proposed for the precoding system. With different targets, the power distribution strategies are given for different QoS.更多还原