文档介绍：OFDMA
南京邮电大学硕士研究生学位论文摘要
摘要
在未来的宽带无线通信系统中,存在两个最严峻的挑战:多径衰落信道和频谱效率。由
于正交频分复用(OFDM)技术在抗多径衰落和高速传输等方面的强大优势,使该技术成为
第四代移动通信的一个关键技术。而在该技术基础上发展出的正交频分多址(OFDMA ),
也成为目前无线接入技术的研究重点之一。因此基于 OFDMA 系统的资源分配成为目前第
四代移动通信研究的一个热点话题。
本文首先对移动通信及资源分配技术的发展进行了回顾,其次介绍了 OFDMA 系统及
其资源分配的基本概念、原理。然后对OFDMA 系统的自适应资源分配技术(子载波分配技
术、比特分配技术、功率分配技术)进行了研究,分析了贪婪算法,最小用户容量最大化算
法,Ian 算法,Hui 算法等几种经典的资源分配算法。
本文最后提出了一种容量和公平性可控的 OFDMA 系统下行资源分配的新算法。在总
功率,误码率和速率比例受限的条件下,它能够最大限度地提高整个系统的容量。未来的
通信系统应同时考虑容量和公平性。因此这种新算法引入了一个新的步骤来重新排列用户
间的子载波,以达到提高速率和比例公平之间的均衡。这种均衡可以通过均衡因子( TF)
得到控制。仿真结果表明,这种容量和公平性可控的新机制可以适用于未来的服务质量
(QoS)可控的 OFDMA 系统。
关键词:OFDMA,自适应资源分配,均衡,容量,公平性
I
Keywords: OFDMA; adaptive resource allocation; tradeoff ; capacity ; fairness
南京邮电大学硕士研究生学位论文 Abstract
Abstract
In the future broadband munication systems, it exists two most critical
challenges: multipath fading channel and frequency efficiency. Orthogonal frequency division
multiplexing (OFDM) technology had enormous advantages in the anti-multipath fading and
high-speed transmission, they made OFDM as a key technology of the fourth-generation mobile
technology. Orthogonal frequency division multiple access (OFDMA) based on OFDM also
became a research point in wireless access technology research. Therefore, the research of
resource allocation based on OFDMA became as a hot topic in the study of the current fourth-
generation munications.
Firstly, the development of munications and resource allocation techniques were
reviewed. Secondly, the basic concepts and principles about OFDMA systems and resource
allocation techniques were given. Thirdly,the adaptive resource allocation techniques (subcarrier
allocation technique, bit allocation technique and power allocation technique) about OFDMA
systems were researched, some typical resource allocation algorithms, including greedy
algorithm, Max-Min algorithm, Ian algorithm and Hui algorithm, are analyzed.
Finally,a new algorithm with controllable capacity and fairness is p