（毕业设计论文）《基于天线选择的准正交空时码的自适应设计》.doc

基于天线选择的准正交空时码的自适应设计 通信工程专业 [摘要] 为了能在满足空时分组码完全分集的同时尽可能降低译码复杂度提出了准正交空时分组码的自适应设计方案在准正交空时分组码的编码结构上添加自适应系数，关键词 Adaptive Design 　and Antenna Selection　for Quasi-Orthogonal Space-Time Block Codes Liu BiFang NO:2006957002, Communication Engineering Major,2010 ChengYi College of Jimei University Abstract In order to satisfy space-time block codes are completely diversity and reduce decoding complexity, improve the system ber performance, In understanding the space-time block codes of coding and decoding method,this paper proposes an adaptive scheme based on the antenna selection, in which the adaptive coefficients are added on prospective orthogonal space-time block codes, to solve the problem on the zero crossing, the resulting channel matrix is of orthogonal, and the inter-symbol interference string are erased on the systems,reduce the maximum likelihood decoding complexity, so as to improve the performance of the system. Paper mainly Jafarkhani code for example is deduced QSTBC adaptive coding and decoding algorithm and average signal-to-noise ratio,and served as antennas selection criteria. Simulation results show that, there QSTBC choice of adaptive antenna system BER performance better than only choice of system performance antenna, no QSTBC system performance antenna choose the worst, In the same SNR conditions, using adaptive joint receive antennas selection system ber performance is the best. Key words quasi-orthogonal space-time block code adaptive antennas selection selection criteria instantaneous output SNR 目录 引言 1 第1章 绪论 2 1.1移动通信的发展现状 2 1.2 MIMO技术的发展 3 第2章 基于正交设计的空时分组码 6 2.1 Alamouti发射分集方案 6 2.2 准正交空时分组码的编码译码方法 9 第3章 自适应QSTBC的编码译码方法和平均信噪比 11 3.1 TBH与Jafarkhani自适应QSTBC的编码方法 11 3.2 自适应QSTBC的译码 11 3.2.1 以Jafarkhani 为例推导自适应QSTBC的译码算法 11 3.2.2 自适应QSTBC两种译码算法的比较研究 16 3.3 自适应QSTBC的平均信噪比表达式 17 3.3.1 Jafarkhani码的平均信噪比表达式 17 3.3.2 TBH码的平均信噪比表达式 18 第4章 自适应QSTBC的建模与仿真 19 4.1 仿真软件Matlab