• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Channel estimation and data detection for mobile MIMO OFDM systems.
【24h】

Channel estimation and data detection for mobile MIMO OFDM systems.

机译：移动MIMO OFDM系统的信道估计和数据检测。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Designing spectral efficient, high-speed wireless links that offer high quality-of-service and range capability has been a critical research and engineering challenge. In this thesis, we mainly address the complexity and performance issues of channel estimation and data detection in multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems over time-varying channels.; We derive the probability density function (pdf) expressions of the condition number (i.e., the maximum-to-minimum-singular-value ratio, MMSVR) of the channel state information matrix of MIMO OFDM systems. It is shown that this ratio is directly related to the noise enhancement in open-loop systems and provides a significant insight on the system capacity.; A decision-directed (DD) maximum a posteriori probability (MAP) channel estimation scheme of MIMO systems is derived. Error performance of a zero-forcing receiver with the DD MAP and perfect channel estimates is provided and compared. This scheme has a low complexity and can be applied to time-varying Rayleigh fading channels with an arbitrary spaced-time correlation function.; We propose an iterative channel estimation and data detection scheme for MIMO OFDM systems in the presence of inter-carrier-interference (ICI) due to the nature of time-varying channels. An ICI-based minimum-mean-square error (MMSE) detection scheme is derived. An expectation-maximization (EM) based least square (LS) channel estimator is proposed to minimize the mean-square error (MSE) of the channel estimates and to reduce the complexity of the implementation. With the estimate of the channel and initially detected symbols, ICI is estimated and removed from the received signal. Thus more accurate estimation of the channel and data detection can be obtained in the next iteration.; An EM-based MAP channel estimator is derived by exploiting the frequency/time correlation of the pilot and data sub-carriers. Performance comparison is made between the proposed schemes and the ideal case---time-invariant channels and perfect channel estimation. We optimize the data transmission by exploiting the long term correlation characteristics. The transmitted data is successively detected without an error floor in spatially correlated channels.; The algorithms proposed in this thesis allow low-complexity implementation of channel estimation and data detection for MIMO OFDM systems over timevarying fading channels, while providing good error performance.
机译：设计提供高服务质量和范围能力的频谱高效，高速无线链路一直是研究和工程上的关键挑战。本文主要研究时变信道上多输入多输出（OFDM）正交频分复用（OFDM）系统中信道估计和数据检测的复杂性和性能问题。我们导出MIMO OFDM系统的信道状态信息矩阵的条件数的概率密度函数（pdf）表达式（即最大与最小奇异值之比MMSVR）。结果表明，该比率与开环系统中的噪声增强直接相关，并提供了有关系统容量的重要见解。推导了MIMO系统的决策导向（DD）最大后验概率（MAP）信道估计方案。提供并比较了具有DD MAP和完美信道估计的零强制接收器的错误性能。该方案具有低复杂度，并且可以应用于具有任意间隔时间相关函数的时变瑞利衰落信道。由于时变信道的性质，我们提出了在存在载波间干扰（ICI）的情况下用于MIMO OFDM系统的迭代信道估计和数据检测方案。推导了基于ICI的最小均方误差（MMSE）检测方案。提出了一种基于期望最大化（EM）的最小二乘（LS）信道估计器，以最小化信道估计的均方误差（MSE）并降低实现的复杂性。利用信道估计和最初检测到的符号，ICI被估计并从接收信号中去除。因此，可以在下一次迭代中获得更准确的信道估计和数据检测。通过利用导频和数据子载波的频率/时间相关性，得出基于EM的MAP信道估计器。在所提出的方案与理想情况-时不变信道和完美信道估计之间进行性能比较。我们通过利用长期相关特性来优化数据传输。在空间相关的信道中连续检测发送的数据而没有错误底限。本文提出的算法允许在时变衰落信道上以低复杂度实现MIMO OFDM系统的信道估计和数据检测，同时提供良好的错误性能。

著录项

  • 作者

    Gao, Jie.;

  • 作者单位

    Oregon State University.;

  • 授予单位 Oregon State University.;
  • 学科 Engineering Electronics and Electrical.
  • 学位 Ph.D.
  • 年度 2005
  • 页码 118 p.
  • 总页数 118
  • 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

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号