【作者】 张健；

【导师】 胡宏林；

【作者基本信息】 中国科学院研究生院（上海微系统与信息技术研究所） ， 通信与信息系统， 2008， 硕士

【摘要】 随着人们对于互联网需求的日益增长,通信的移动化和宽带化是必然的发展趋势,作为“最后一公里”的宽带无线接入技术有广泛的应用前景,以IEEE802.16e标准为基础的WiMAX技术已经成为宽带无线技术的主流。WiMAX作为一种面向无线城域网(WMAN)的宽带接入方案,以其优异的性能和广阔的市场前景而倍受关注,已经得到了很多运营商的认可。WiMAX系统的网络质量、覆盖、容量之间有着非常复杂的动态关系,加上多种类型业务的引入,因此,很难简单地从理论上准确地对系统整体性能进行分析。目前,使用软件仿真技术进行移动通信协议研究、网络规划、性能评估和优化已经成为了一种基本手段。本文的工作分为系统仿真平台设计实现和系统性能评估两个方面。通过对无线通信系统仿真模型的研究,结合IEEE 802.16e协议,基于OPNET网络仿真软件,设计和开发了WiMAX系统级仿真平台。详细阐述了无线资源调度器和无线信道模拟的实现。而且对小区覆盖、不同子载波排列方式的扇区吞吐量以及混合自动重传(HARQ)进行了系统性能仿真评估。本文最后针对一种具体的实时业务,比较分析了协议规定的三种实时调度机制,并在具体实现中提出了改进方案。系统仿真结果表明,改进的方案减小了用户的上行接入时延,提高了通信质量。更多还原

【Abstract】 With the growing demand for the Internet Network, the mobilization and broadband is the inevitable development trends of future communication systems. Broadband Access Technologies has a wide application prospect as the last-mile technologies. WiMAX based on IEEE 802.16e has become a major technology for broadband access. As a broadband access scheme for Wireless Metropolitan Area Networks (WMAN), WiMAX has received much attention for its outstanding performance and wide market prospects, and has been approbated by many network operators.The dynamic relationship among quality, coverage, capacity of WiMAX network is very complicated. In addition, many kinds of services are being introduced into the WiMAX network. As a result, it is difficult to analyze the whole performance of the system accurately in theory. Nowadays, software simulation technique has become a popular basic method for mobile communication protocol research, network planning, performance evaluation and optimization.The work of this dissertation could be divided into two parts, one part is the design and implementation of system level simulation platform, and the other part is system performance evaluation. Through the research of simulation models for wireless communication system, combined with the IEEE 802.16e protocol, we designed and developed system level simulation platform for WiMAX system based on OPNET network simulation software. This paper addressed the implementation of radio resource scheduler and radio channel simulation in detail. Moreover, we made system performance simulation for cell coverage, sector throughput under different subcarrier permutation, and hybrid automatic repeat request(HARQ). At the last section, we analyzed and compared the three real-time scheduling schemes specified in the protocol when they were used for a specific type of real-time service, and proposed an improved scheduling scheme. System level simulations show that the proposed scheme reduced the user’s uplink access delay, and consequently improved the communication quality.更多还原