【作者】 陆彦辉；

【导师】 乐光新；

【作者基本信息】 北京邮电大学 ， 通信与信息系统， 2006， 博士

【摘要】 移动通信和互联网的高速发展，使得人们对宽带无线接入的需求越来越迫切。人们期望，未来的移动通信系统(B3G，Systems Beyond3G)能够提供更高的数据速率，支持更多的用户并且满足多种业务的不同服务质量(QoS，Quality of Service)要求。 在所有的B3G候选方案中，正交频分多址接入(OFDMA， Orthogonal Frequency Division Multiple Access)系统受到广泛关注。由于使用快速傅立叶变换及其逆变换实现OFDM(Orthogonal Frequency Division Multiplexing)符号的调制和解调，OFDMA系统不但实现简单，而且能够克服宽带无线通信中由多径效应引起的严重的符号间干扰(ISI，Inter-Symbol Interference)。应用先进的无线资源管理技术，充分利用无线信道的衰落特性，OFDMA系统能够增加频率分集和多用户分集增益，提高系统容量，满足多方多媒体业务的通信需求。因此本文把多用户多业务OFDMA系统中的无线资源管理技术作为研究的重点。 研究无线资源管理技术，确定系统的容量极限非常重要。本文首先用多用户信息论推导了MIMO-OFDM(Multiple Input Multiple Output)系统在衰落信道下的广播信道容量、多用户分集增益和最优发送策略，并且分析了多径时延扩展、信噪比及天线数对系统容量的影响。结果表明：天线数和平均接收信噪比是决定MIMO-OFDM系统信道容量的关键因素，天线数越多或者接收信噪比越大，信道的容量越大；系统带宽固定后，信道容量几乎不受多径时延扩展／子载波数的影响；慢衰落信道下的最大信道容量可以使用空-频两维注水算法得到；而多用户OFDM系统的最大信道容量则可以用平均分配发送功率的方法逼近。 考虑到对有限的无线资源的有效利用是提高频谱效率的关键，论文进一步研究了多用户OFDMA系统中的无线资源分配算法，并且提出了一种适用于多业务OFDMA系统的自适应子载波分配和比特加载方案。该算法按照业务的QoS把用户分类并划分优先级，然后根据不同的优先级使用不同的优化目标为其分配资源。对时延和时延抖动敏感的业务，通过把最大化系统吞吐量和降低中断概率作为优化目更多还原

【Abstract】 Rapid progress of mobile communication and internet networks in recent years has seen a dramatically growing demand for wireless multimedia services requiring reliable and high-speed data transmission over a wireless channel. One of the most challenges for the future wireless communication systems (B3G, systems beyond 3G) is to support a large number of subscribers and to ensure the fulfillment of quality-of-service (QoS) requirements, given the limited availability of frequency spectrum.To solve this issue, many methods have been proposed, among which orthogonal frequency division multiple access (OFDMA) system is a promising candidate because of its ability to combat intersymbol interference (ISI) and flexibility for adaptive frequency channel control. Recently, adaptive radio resource management for multiuser OFDMA system has attracted enormous research interest, which can provide frequency domain diversity as well as multi-user diversity gain and improve effectively system performance.This dissertation focuses on radio resource management for adaptive OFDMA system, including adaptive radio resource allocation, downlink packet scheduling and call admission control. There are four major results in the dissertation.First, the ergodic capacity and optimal power allocation policy of broadband MIMO-OFDM systems in wireless fading channels are derived to determine the capacity limits of OFDM systems. Further, the sum-rate capacity and multiuser diversity gain of MIMO-OFDM system are shown from a multiuser information theory point of view. The results indicate that: the channel capacity of MIMO-OFDM system grows with the number of antennas and average received Signal Noise Ratio (SNR),更多还原