Signal Processing for Wireless Communications over Triply Selective Fading Channels

由于有限的频谱以及对高数据速率和高质量服务的日益增长的需求，多用户多输入多输出（MIMO）通信很可能成为未来无线通信网络的工具。对MIMO无线通信的研究已经进行了大约十年。使用简化或理想化的衰落信道模型，已经开发了各种MIMO信号处理方法和信息理论结果。在实际衰落信道中，MIMO通信的收发机设计工作相对较少，这些信道通常经历空间选择性、时间选择性和频率选择性衰落。这种真实的衰落被称为三重选择性衰落。三重选择性衰落包含双选择性作为一种特殊情况，但它不是一个微不足道的扩展，特别是在基于容量的收发器设计方面。本计画研究三重选择性衰落信道下多用户MIMO通信的几个关键问题。首先，分析了三重选择性衰落及其相关矩阵对多用户MIMO多址接入信道（MAC）的遍历容量、中断容量、网络吞吐量和差错性能的影响，以帮助设计基于容量的传输策略。其次，设计了一种协作多用户MIMO MAC收发机，该收发机只需要提供相关矩阵就可以优化传输策略，并研究了在低系统复杂度下最大化容量增益和系统性能的设计方法。第三，研究了基于信息容量的收发机的信号处理算法，包括单载波和多载波调制、多用户MIMO信道估计、多用户MIMO信道均衡和检测。这些课题的研究将为多用户MIMO三重选择性衰落信道的遍历容量和中断容量提供可行的解决方案，迄今为止，还没有成功地解决。

Multiuser multiple input multiple output (MIMO) communication is likely to become instrumental for future wireless communication networks due to limited frequency spectrum and increasing demand for high data rate and high quality services. Research on MIMO wireless communication has been going on for about a decade. Various MIMO signal processing methods and information theoretical results have been developed using simplified or idealized fading channel models. Relatively less work has been done for the transceiver design of MIMO communications over realistic fading channels, which usually undergo space-selective, time-selective, and frequency-selective fading. This realistic fading is referred to as triply selective fading. The triply selective fading contains doubly selective as a special case but it is not a trivial extension, especially in terms of capacity-based transceiver design. The project investigates several key problems in multiuser MIMO communications over triply selective fading channels. First, it analyzes the effects of triply selective fading and its correlation matrices on the ergodic capacity, outage capacity, network throughput, and error performance of multiuser MIMO multiple access channels (MAC) to assist in the design of capacity-based transmission policies. Secondly, it designs a cooperative multiuser MIMO MAC transceiver that requires only the correlation matrices be provided to optimize transmission policies, and investigate the design methodology for aximizing capacity gains and system performances with low system complexity. Thirdly, it develops signal processing algorithms for the information capacity-based transceivers including single carrier and multi-carrier modulations, multiuser MIMO channel estimation, and multiuser MIMO channel equalization and detection. The research in these topics will provide viable solutions for the ergodic capacity and outage capacity of multiuser MIMO triply selective fading channels that have, to date, not been successfully addressed.