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Space-time block codes for wireless systems: Construction, performance analysis, and trellis coded modulation.

机译：无线系统的时空分组码：构造，性能分析和网格编码调制。

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摘要

Space-time codes are effective means by which to combat fading by exploiting diversity in both spatial and temporal dimensions. In this work, code performance and design are considered in the context of Direct-Sequence Code-Division Multiple-Access (DS-CDMA) systems. The performance criteria, diversity gain and coding gain, are redefined as functions of the spreading code correlation. Uplink and downlink scenarios are both analyzed in multipath fading channels. Optimal codes are searched for both spread and non-spread systems. To reduce the decoding complexity, suboptimal linear decoders are classified and analyzed. The asymptotic achievable diversity level is derived when the number of receive antennae is large. Motivated by the structures found in computer optimized codes, via distance preserving isometries, Space-Time Block Codes (STBCs) are constructed bottom-up by optimizing the coding gain layer-by-layer and reusing the optimized structure. STBCs constructed in this way are dubbed Nonlinear Hierarchical Codes (NHCs). NHCs are essentially a generalization of Slepian's group codes for the Gaussian channel to the multiple-input multiple-output quasi-static fading channel. NHCs consistently offer comparable or significantly better performance than constrained designs (orthogonal or unitary). Systematic Regular MTCM (RMTCM) design procedures are proposed to exploit the layered structure of NHCs which leads to optimized designs for various rates/block sizes/constellation sizes. The match between the distance spectrum of NHCs to the regular trellis structure optimizes coding gain directly, and full diversity is naturally maintained given the full rank of the constituent NHCs. Several factors which affect performance in both quasi-static and fast block fading channels are analyzed and exploited to improve the overall performance. Set expansion is used to improve high rate RMTCM designs. RMTCM offers the best tradeoff between performance and complexity among STTC and (interleaved) serial concatenated system.
机译：时空码是有效的手段，可通过利用时空维度的多样性来对抗衰落。在这项工作中，在直接序列码分多址（DS-CDMA）系统的上下文中考虑了代码性能和设计。将性能标准，分集增益和编码增益重新定义为扩展码相关性的函数。上行链路和下行链路场景都在多径衰落信道中进行了分析。同时搜索扩展和非扩展系统的最佳代码。为了降低解码复杂度，对次优线性解码器进行分类和分析。当接收天线的数量很大时，可以得出渐近可达到的分集等级。受计算机优化代码中存在的结构的激励，通过保持距离的等距关系，通过逐层优化编码增益并重新使用优化后的结构，自底向上构建了空时分组代码（STBC）。以此方式构造的STBC被称为非线性层次码（NHC）。 NHC本质上是将高斯信道的Slepian组码推广到多输入多输出准静态衰落信道。 NHC始终提供比受限设计（正交或一体式）可比或明显更好的性能。提出了系统的常规MTCM（RMTCM）设计程​​序来利用NHC的分层结构，从而导致针对各种速率/块大小/星座图大小的优化设计。 NHC的距离谱与规则网格结构之间的匹配直接优化了编码增益，并且给定组成NHC的完整等级，自然可以保持完整的多样性。分析和利用了一些影响准静态和快速块衰落信道中性能的因素，以改善整体性能。集扩展用于改善高速率RMTCM设计。 RMTCM在STTC和（交错）串行串联系统之间的性能和复杂性之间提供了最佳折衷。

著录项

  • 作者

    Geng, Jifeng.;

  • 作者单位

    University of Southern California.;

  • 授予单位 University of Southern California.;
  • 学科 Engineering Electronics and Electrical.
  • 学位 Ph.D.
  • 年度 2004
  • 页码 144 p.
  • 总页数 144
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 无线电电子学、电信技术;
  • 关键词

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