宽带无线城域网实时通信系统中功率控制技术的研究与实现

【作者】 彭静；

【导师】 刘光祜；

【作者基本信息】 电子科技大学 ， 电路与系统， 2007， 硕士

【摘要】 近年来，随着Internet的进一步普及，网络服务已经深入到大众生活的方方面面，网络已经成为人们日常生活中不可缺少的一部分，网络IP化，无线化也是现在网络发展的必然趋势。互联网工程任务组(IETF)在无线领域针对不同的市场需求和应用模式制定了不同的标准，包括应用于无线个人网(WPAN)的IEEE802.15标准，应用于无线局域网的(WLAN)IEEE 802.11标准，以及IEEE 802.16无线城域网标准(WMAN)等等。无线城域网(IEEE 802.16)标准一经提出，就因为其高带宽，低投入等优点成为当前热点研究的无线网络技术。在无线城域网通信系统中，采用功率控制技术可以降低OFDM无线系统的同频道干扰，从而增加系统容量。本论文对无线城域网通信系统中的功率控制问题进行了深入研究，完成的主要工作和创新可概括如下：首先，本文简要介绍了功率控制技术的发展状况，并对几种经典的功率控制算法进行了系统的归纳总结，得出了这些功率控制算法各自的优缺点。然后，对IEEE802.16协议中提出的功率控制算法作了详细的介绍和理论分析，分析了该算法中所存在的缺点，将此作为后续研究和待解决的重点问题。同时，对本文的无线城域网实验平台所采用的软硬件系统分别作了较为详细地介绍。其次，针对本人研究工作的重点，对无线城域网实时通信系统中的功率控制技术的实现提出了上行开环功率控制、上行闭环功率控制、上行开环／闭环联合攻率控制和上行／下行结合的功率控制这四种可选方案，并对这几种方案进行了分析比较，得出一种相对优化的实现方案。将该方案在Linux OS下以网络驱动程序的方式加以实现，包括基站功率控制模块和移动台功率控制模块。最后，针对以上介绍的功率控制方案的实现结果，搭建了实际的实验网络平台，对该实验网络进行了相应的参数配置，并在该硬件平台上运行了带有功率控制模块的无线城域网基站和移动台软件系统，对其中的功率控制部分作了详细的测试，验证了本文提出的OFDMA的功率控制方案在无线城域网实时通信系统中的可行性和有效性。更多还原

【Abstract】 In recent years, along with the popularization of the Internet, the network servicehas penetrated into every aspect of people’s lives and the network becomes anindispensable part of people’s daily lives. Now the network is converting to a wirelessand Internet-protocol-based(IP-based) network and it is the inevitable direction of thedevelopment of the network. The Internet Engineering Task Force(IETF) hasconstituted different sets of standards to surport different market needs in the wirelessfield, including the standards of the IEEE802.15 which is applied to the wirelesspersonal area network(WPAN), the IEEE802.11 which is applied to the wireless localarea network(WLAN), the IEEE802.16 which is applied to wireless metropolitannetwork(WMAN) and so on. As it is presented currently, the WMAN standard(IEEE802.16) becomes one of the hottest wireless networking technology becuase of itsbroad bandwidth, low cost and other merits.In order to reduce the co-channel interferences of the OFDM wireless system sothat we can increase the capacity of the system, we can adopt power control technologyin the WMAN communitation system. This dissertation mainly focuses on reporting myresearches on the problem area relating to the power controlling in the WMAN realtimecommunication system. The main contents of my researches are generalized below:Firstly, the dissertation briefly introduces the evolution of the power controltechnology. Based on these, it analyses several classical power control algorithms andsummarizes the merits and demerits of them. After this, the power control algorithm ofIEEE802.16 is also introduced and analyzed. This dissertation points out itsshortcomings, which will be the problems to be solved. Additionally, it introduces thesoftware system of the realization of the IEEE802.16e MAC as well as the hardwaresystem, which is implemented by the picoChip company, to support the PHY of thatspecification.Secondly, aimed at the emphasis on the research work, this dissertation alsopresents four implementing schemes of the power controlling algorithms in the WMANcommunication system: the uplink open loop power control scheme, the uplink closed loop power control, the uplink open loop and closed loop combined power controlscheme and the uplink and downlink combined power control scheme. Based on thecomparison on the four schemes, it obtains an optimized scheme to implement thepower control algorithms in the WMAN communication system. Then I implement thescheme under Linux OS as a part of the network driver with all the functions of thepower control module of the base station and the mobile station.Finnally, we build a test bed of WMAN communication system, which is basedon the IEEE802.16e specification. The power control algorithm is applied to it. We testthe performance of power control algorithm on the test bed. The testing result showsthat the proposed power control scheme in this dissertation is validated and feasible.更多还原