贝尔实验室分层空时码-迫零算法-CD

集美大学毕业论文 李明忠：贝尔实验室分层空时码接收结构分析-迫零算法

贝尔实验室分层空时码接收结构分析

--迫零算法

[摘要] 分层空时编码技术是提高无线信道传输速率和容量的一种非常有效的方法。在

无需提高信号发射功率和额外增加带宽的情况下就可以大幅度的提高系统容量。但是，分层空时编码无法获得最大分集增益，所以接收端在恢复信号时选用的译码算法对系统性能至关重要。在平坦瑞利衰落环境下，本文首先对MIMO（Multiple Input Multiple Output，MIMO）的信道模型和容量进行分析，重点研究了它的容量仿真方法。在此基础上，研究了贝尔实验室分层空时（Bell Laboratories layered Space-Time，BLAST）的发射和接收结构，掌握了三种分层空时编码，包括水平分层（Horizontal Bell Laboratories Layered Space-Time ,H-BLAST）、垂直分层（Vertical Bell Laboratories layered Space-Time ,V-BLAST）和对角分层（Diagonal Bell Laboratories Layered Space-Time ,D-BLAST），并给出了接收表达式。接着对接收端的几种常用的译码算法进行介绍，重点介绍迫零(Zero forcing ,ZF)算法，本文还就它的信道适用性和采用优化解码顺序降低它的误码率进行了研究。根据这些理论，本文通过计算机的仿真方法，对MIMO系统容量和天线的关系及MIMO系统容量和信噪比的关系进行了仿真分析，特别地，针对使用BPSK调制时三种编码的容量进行了仿真比较。在同样的环境和条件下，本文还对使用迫零算法的不同分层空时码的误码率进行了仿真，并和最小均方误差算法（Minimum Mean Square Error，MMSE）进行比较。最后针对迫零算法的信道适用性和优化解码顺序进行了仿真。

[关键词] BLAST MIMO 平坦瑞利衰落 迫零算法 容量

摘要

i

集美大学毕业论文 李明忠：贝尔实验室分层空时码接收结构分析-迫零算法

The Analysis of the Receiver Architecture for BLAST

--ZF(Zero Forcing)

Abstract Bell labs Space–Time (BLAST or LST) coding technology is an available way to

enhance the data rate and channel capacity in wireless communication .Without increasing transmitting power or expanding bandwidth, the capacity can be improved greatly . However, LST coding achieve high spectral efficiency at the cost of partial diversity gain and cannot obtain the maximum diversity gain. As a result, the detection algorithm at the receiver is the key factor to improve system performance. At the environment of Fad Rayleigh Channel, At the environment of Fad Rayleigh Channel , the paper firstly analyses the channel model and channel capacity for MIMO（Multiple Input Multiple Output，MIMO）,specially investigate the method of capacity simulation. On this basis, the paper studies the BLAST transmitting and receiving architecture, and introduce three types of LST coding,including Horizontal Bell Laboratories Layered Space-Time(H-BLAST),Vertical Bell Laboratories layered Space-Time(V-BLAST) and Diagonal Bell Laboratories Layered Space-Time (D-BLAST),then the expression at the receiver is given . Then the paper goes to introduce several commonly used algorithm , Zero forcing (ZF)algorithm is introduced mainly. The paper even investigates the applicability of ZF algorithm and the optimal decoding order which is used to decrease the error probability of the ZF algorithm .According to these theories , two relationships , MIMO channel capacity to the numbers of antennas and the MIMO channel capacity to the Signal-to-noise(SNR), are then simulated by using the method of computer , specially the capacity of three coding are compared under using BPSK modulation. With the same environment and conditions, the paper simulates the error probability for the different LST coding which all use ZF algorithm, then the results are compare to Minimum Mean Square Error(MMSE). Finally , the applicability and the optimal decoding order of ZF algorithm are simulated .

Key words LST MIMO Fad Rayleigh Channel ZF Capacity Abstract ii

目录

目录

摘要 ............................................................... i Abstract .......................................................... ii 目录 ............................................................. iii 引言 ............................................................... 1 第1章 多输入多输出模型及容量 ...................................... 2

1.1 概述 ........................................................ 2 1.2 平坦瑞利衰落信道下MIMO系统模型 ............................. 2 1.3 平坦瑞利衰落信道MIMO容量推导 ............................... 3 第2章 BLAST结构分析及算法研究 ..................................... 7

2.1 概述 ........................................................ 7 2.2 BLAST发射机 ................................................ 7

2.2.1 分层空时码模型 ........................................ 7 2.2.2 分层空时码的编码方案 .................................. 8 2.3 常用译码算法 ............................................... 10

2.3.1 接收端表达式 ......................................... 10 2.3.2 最大似然译码算法 ..................................... 11 2.3.3 迫零算法 ............................................. 12 2.3.4 最小均方误差干扰抑制和干扰抵消 ....................... 12 2.4 迫零干扰抑制和干扰抵消算法 ................................. 13

2.4.1 迫零算法 ............................................. 13 2.4.2 迫零算法举例说明 ..................................... 14 2.4.3 改进迫零算法 ......................................... 16

第3章 容量分析及其仿真 ........................................... 17

3.1 概述 ....................................................... 17 3.2 仿真原理 ................................................... 17 3.3 MIMO容量仿真及分析 ........................................ 19

3.3.1 MIMO容量仿真及分析 ................................... 19 3.3.2 MIMO信道可靠性仿真及分析 ............................. 20 3.4 结合编码译码算法的容量仿真 ................................. 22 第4章 误码分析及其仿真 ........................................... 25

4.1 概述 ....................................................... 25 4.2 仿真原理 ........................................ …… 此处隐藏：6122字，全部文档内容请下载后查看。喜欢就下载吧 ……