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Multi-layered space frequency time codes.

机译：多层空间频率时间码。

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摘要

This dissertation focuses on three major advances on multiple-input multiple-output (MIMO) systems. The first studies and compares decoding algorithms for multi-layered space time coded (MLSTC) systems. These are single user systems that combine spatial multiplexing and transmit diversity. Each layer consists of a space time code. The detection algorithms are based on multi-user detection theory. We consider joint, interference nulling and cancellation, and spatial sequence estimation algorithms. As part of joint detection algorithms, the sphere decoder is studied and its complexity is evaluated over MIMO channels. The second part contributes to the field of space frequency time (SFT) coding for MIMO-OFDM systems. It proposes a full spatial and frequency diversity codes at much lower number of trellis states. The third part proposes and compares uplink scheduling algorithms for multiuser systems with spatial multiplexing. Several scheduling criteria are examined and compared.;The capacity and error rate study of MLSTBC reveals the performance of the detection algorithms and their advantage over other open loop MIMO schemes. The results show that the nulling and cancellation operations limit the diversity of the system to the first detected layer in serial algorithms. For parallel algorithms, the diversity of the system is dominated by the performance after parallel nulling. Theoretically, parallel cancellation should provide full receive diversity per layer but error propagations as a result of cancellation prevent the system from reaching this goal. However, parallel cancellation provides some gains but it doesn't increase the diversity. On the other hand, joint detection provides full receive diversity per layer. It could be practically implemented with sphere decoding which has a cubic complexity at high SNR.;The results of the SFT coding show the superiority of the IQ-SFT codes over other codes at the same number of sates. The IQ-SFT codes achieve full spatial and frequency diversity at much lower number of trellis states compared to conventional codes. For V-BLAST scheduling, we propose V-BLAST capacity maximizing scheduler and we show that scheduling based on optimal MIMO capacity doesn't work well for V-BLAST. The results also show that maximum minimum singularvalue (MaxMinSV) scheduling performs very close to the V-BLAST capacity maximizing scheduler since it takes into account both the channel power and the orthogonality of the channel.
机译：本文重点研究了多输入多输出（MIMO）系统的三项主要进展。首先研究并比较了多层空时编码（MLSTC）系统的解码算法。这些是结合了空间复用和传输分集的单用户系统。每层都包含一个时空代码。该检测算法基于多用户检测理论。我们考虑联合，干扰消除和抵消以及空间序列估计算法。作为联合检测算法的一部分，研究了球形解码器，并在MIMO信道上评估了其复杂度。第二部分有助于MIMO-OFDM系统的空频时间（SFT）编码领域。它提出了在格状状态数量少得多的情况下的完整空间和频率分集码。第三部分提出并比较了具有空间复用的多用户系统的上行调度算法。研究并比较了几种调度标准。MLSTBC的容量和错误率研究揭示了检测算法的性能及其相对于其他开环MIMO方案的优势。结果表明，归零和消除操作将系统的多样性限制为串行算法中的第一个检测到的层。对于并行算法，系统的多样性主要取决于并行归零后的性能。从理论上讲，并行消除应在每层提供完整的接收分集，但是消除引起的错误传播会阻止系统达到此目标。但是，并行消除可以带来一些好处，但不会增加分集。另一方面，联合检测可提供每层完整的接收分集。它可以在高信噪比下具有三次复杂度的球形解码来实际实现。SFT编码的结果表明，在相同数量的状态下，IQ-SFT代码优于其他代码。与传统代码相比，IQ-SFT代码在网格状态数量少得多的情况下实现了完整的空间和频率分集。对于V-BLAST调度，我们提出了V-BLAST容量最大化调度器，并且表明基于最优MIMO容量的调度对于V-BLAST效果不佳。结果还显示，最大最小奇异值（MaxMinSV）调度的性能非常接近V-BLAST容量最大化调度器，因为它同时考虑了信道功率和信道的正交性。

著录项

  • 作者

    Al-Ghadhban, Samir.;

  • 作者单位

    Virginia Polytechnic Institute and State University.;

  • 授予单位 Virginia Polytechnic Institute and State University.;
  • 学科 Engineering Electronics and Electrical.
  • 学位 Ph.D.
  • 年度 2005
  • 页码 229 p.
  • 总页数 229
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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