【作者】 金奕丹；

【导师】 吴伟陵；

【作者基本信息】 北京邮电大学 ， 信号与信息处理， 2006， 博士

【摘要】 近年来，全球移动通信事业经历着飞速的发展，随着移动用户数的激增和多样化需求的提出，现有以话音业务为主的移动通信系统已难以满足日新月异的需求变化，取而代之的是高速移动数据业务、移动流媒体、手机电视等对带宽等网络资源要求苛刻的新兴业务。因此，具有更大的系统容量、更大的网络带宽且能提供多媒体业务的未来移动通信系统已俨然成为研究热点。 本论文主要针对移动通信系统中接收端的关键技术问题进行了研究，特别是多入多出正交频分复用(MIMO-OFDM)技术、高效信道编码技术、空时编码技术、多用户检测以及迭代检测在其中的应用等。 受Turbo码启发，最近出现的“迭代处理”思想已经在编码和信号处理等诸多领域获得了成功应用。本文的主要工作就是在Turbo码迭代译码原理的基础上，研究迭代检测的关键技术，着重探讨编码MIMO-OFDM系统、DS-CDMA多用户系统、空时编码多用户系统以及交织多址系统的迭代检测技术，并对其接收机架构、检测算法、接收性能及算法复杂度等进行了仿真分析。本论文的主要研究内容如下： 迭代原理及迭代多用户检测技术研究：本部分内容简要回顾了迭代思想来源、迭代检测概念、基本原理及传输模型，随后研究了几种常用的迭代检测算法及最新提出的几种性能优异的迭代检测算法，接着阐述了迭代思想的应用；同时重点讨论了迭代多用户检测技术的原理、技术特点、系统模型、常用检测算法以及未来的发展趋势等。 MIMO-OFDM系统迭代接收机架构及检测算法：MIMO-OFDM系统具有能够同时增强空间复用技术和OFDM技术的能力，有利于增加系统容量，适合高速率数据传输。本部分内容首先回顾了MIMO-OFDM系统原理及技术特点，描述了MIMO-OFDM系统模型，针对传统判决反馈均衡器误差传播的缺陷，重点研究了Turbo编码MIMO-OFDM系统的高性能检测算法。运用迭代思想，提出一种用于MIMO-OFDM系统的低复杂度的迭代IPDA检测算法，检测器与信道译码器之间迭代交换外信息，实现信道均衡与信道译码的迭代更新，以充分利用已获得的信息；其新颖之处是把接收信号向量建模为高斯随机向量，通过迭代求解均值向量和协更多还原

【Abstract】 With the number of subscribers increasing and service requirements diversified, universal telecommunication system overrides the current mobile telecommunication system, which can not satisfy the diverse requirements. Therefore, UMTS and the future mobile communication systems providing large system capacity and multimedia service capability have absorbed much attention.To combat the current technical obstacles, several key techniques in receiver of future mobile telecommunication system have been innovated in this dissertation, and the purpose is focused on the application of MIMO-OFDM technology, high efficient channel coding technology, space-time coding technology, multiuser detection and iterative detection, and so on.Turbo principle, derived from Turbo-codes, has been broadly applied to coding and signal processing area. The main jobs in this dissertation has been emphasized on the key technologies of iterative detection based on a "Turbo principle", such as in coded MIMO-OFDM systems, coded DS-CDMA multi-user systems, space-time block-coding multi-user systems, multi-user MIMO-IDMA systems, and has proposed the innovative receiver architectures, simulated and anylized the detection algorithm, and its’ performances and complexities. The main works include:The research on the turbo principle and iterative multiuser detection technology: In this part, an overview about the orgin of turbo principle, the concept, transmission model is presented firstly. And then several commonly applied and newly proposed algorithms of iterative detection are introduced, and the application of turbo principle are described in this part; and focusing on the iterative multiuser detection technology, the principle, the technology characteristic, and the system model, the commonly applied detection algorithms and the future development trend are emphasisedly researched.Reduced-Complexity Iterative receiver for Turbo Coded MIMO-OFDM Systems: MIMO-OFDM system is a good choice for high-speed data transmission, which can enlarge the system capability by enhancing the capacity of both the space complexing technology and OFDM technology. In this part, the theory, characteristic and system model of the MIMO-OFDM systems are reviewed firstly. Then high performace detection technology for turbo coded MIMO-OFDM systems is researched to mitigate error propagation, and a receiver infrastructure and a low-complexity iterative detection algorithm are derived. When algorithm processing, extrinsic information is extracted from the detector and the channel decoder in each iteration, and then used as the prior information for the next iteration to realize iterative channel equalization and channel decoding to make full use of the known information. The novelty of the proposed algorithm is to model the receiver signal vector as Gaussian random vector, and get the mean and variance of the detection signal to obtain the optimization. The simulation results更多还原