文档介绍：摘要
近年来 LTE 得到了长足的发展,截至目前全球已有 301 家运营商正在投资和部署 LTE 商用网络。为了满足 4G 通信需求,3GPP 进一步又启动了 LTE-A 项目。随着用户需求不断增长以及频谱日益匮乏,无线资源管理在未来移动通信系统中变得越来越重要,作为无线资源管理的核心,动态资源分配成为合理使用有限频谱资源,提高系统性能改善用户 QoS 的关键。
本文对 LTE-A 中 OFDMA 动态资源分配算法进行了研究,介绍了课题的相关理论,包括 LTE/LTE-A 网络架构、物理层关键技术和资源分配已有算法等,分析了动态资源分配的两种模型:速率自适应(Rate Adaptive, RA)和边值自适应(Margin Adaptive, MA)。
针对多用户 OFDMA 中的速率自适应问题,在子载波分配已经确定的情况下, 提出了一种最优的功率分配算法。传统算法得到的最优功率分配结果是一个多级注水解,需要通过大量迭代才能实现,而本文提出的算法无需迭代同样能达到最优的系统性能,并进行了仿真验证。
P 的边值自适应问题提出了一种实时资源分配算法,该算法将联合优化问题分成三步完成:首先由用户的速率要求及平均信道增益来粗略计算出每个用户所需要的子载波数目;然后根据空间相关度矩阵和信道增益为用户
分配具体的子载波;最后采用一种改进的快速比特加载算法完成比特分配。仿真
结果表明该算法在复杂度和吞吐量之间获得了很好的折中。
关键词:LTE/LTE-A OFDMA 下行 P 动态资源分配
Abstract
In the recent years, LTE has obtained a considerable development, by now more than 301 operators aroung the world have been investing or deploying work. In order to meet the munication needs, 3GPP further initiates the LTE-A project. With the growing demands of users and the scarcity of spectrum, wireless resource management es more and more important in the future munication systems. Therefore, as the core of wireless resource management, dynamic resource allocation is the key to improve system performance and guartanee the user QoS.
This paper studies on the OFDMA dynamic resource allocation algorithm of LTE-A system, describes the related theories, including LTE/LTE-A architecture, the key technologies of the physical layer and the existing resource allocation algorithms etc., analyzes two main models of dynamic resource allocation: rate adaptive problem and margin adaptive problem.
For the Rate adaptive problem in multi-user OFDMA system, an optimal power allocation algorithm is designed in the case that subcarriers have been allocated. In tradional argorithm, the optimal power allocation can be reached through a large number of iterations. however, the proposed algorithm can achieves the optimal solution without iterations, and simulation experiment confirms the theoretical analysis.
For the margin adapt