【作者】 王宇；

【导师】 李乐民； 李少谦；

【作者基本信息】 电子科技大学 ， 通信与信息系统， 2002， 博士

【摘要】 为移动用户提供多种业务服务是未来无线通信网络的主要发展方向。由于CDMA技术具有灵活支持多种业务的优点，因而被第三代移动通信系统所采纳。如何在恶劣的无线传播环境里以及用户运动且相互干扰的情况下为各类业务提供QoS保证，同时充分利用珍贵的无线频谱资源，是基于CDMA技术的第三代蜂窝通信系统、以及未来的无线个人通信系统都必须致力解决的问题。本文从系统设计的角度出发，围绕多业务CDMA蜂窝通信系统的容量性能和三种重要的与无线资源管理有关的算法：功率控制算法、接纳控制算法和分组调度算法进行研究。 对承载具有不同QoS要求的多业务CDMA蜂窝通信系统的容量性能进行研究是系统容量规划所需解决的关键问题之一，同时，有效精确的分析方法有助于我们深入地认识影响CDMA系统小区容量的诸多因素，从而提出相应的解决办法，提高系统的频谱利用率。本文在第二章里首次全面地研究了多业务CDMA蜂窝通信系统的上行链路和下行链路的容量性能。对于上行链路，提出并验证了在多业务环境中，用对数正态分布的随机变量来近似基站接收到的总干扰信号的统计特性可以获得比目前文献中大量采用的高斯近似分析方法更为精确的结果，从而为研究上行链路的容量性能提供了简洁可靠的解析评估方法。对于下行链路，移动台接收到源自不同基站发送的合成信号，其分布特性不易解析得到，提出了计算机仿真的方法来研究下行链路的业务容量性能。在分析中，我们综合考虑了呼叫的到达过程，业务激活因子，无线传播环境和功率控制误差等因素，弥补了目前文献中一些过于简单或理想的假设条件，使之更符合系统的实际情况，以有助于系统的容量规划设计。 功率控制是蜂窝通信系统，尤其是基于CDMA的蜂窝通信系统中资源分配与干扰管理的关键技术之一，有效的功率控制算法能够降低用户间的相互干扰，增加系统容量，对于移动用户而言，还能延长手机的待机时间。本文第三章对多业务CDMA蜂窝通信系统的功率控制问题进行了研究。首次提出了广义SIR平衡的概念，并将现有文献中只能适用于单一业务蜂窝系统的、基于SIR平衡 中文摘要概念的一大类集中式和分布式功率控制算法经改进后能够应用到多业务的CDMA蜂窝通信系统中，增大系统的容量。同时从理论上证明了单一业务蜂窝系统中的SIR平衡问题是广义SIR平衡问题的一个子集，从而完善了基于SIR平衡概念的功率控制算法的理论研究。 CDMA蜂窝通信系统的小区容量是有限的，当小区容量己处于饱和状态时，继续接纳新的用户进入系统，将使己有用户的 QOS无法得到保证。系统必须采取有效的接纳控制策略，使得各类业务的QOS在获得保证的同时，尽可能为更多的用户提供服务。本文第四章对多业务CDMA蜂窝通信系统的接纳控制问题进行了研究。首次提出了基于幻 测量的能够满足多种业务不同 QOS要求的两种接纳控制算法：局部策略和全局策略，弥补了现有文献中基于SIR测量的接纳控制算法无法支持多种业务服务的不足。 以分组交换方式为基于Intenlet的大量非实时数据业务提供服务可以优化系统的频谱利用率。在分组交换网络里，当有多个分组业务流等待接受服务时，必须确定合理的服务规则，安排流的服务顺序和服务时间，以满足各个业务流的 QOS要求，这就是分组调度所要解决的基本问题。本文第五章对 CDMA蜂窝通信系统中的分组调度问题进行了研究。首次提出了综合考虑移动台的信道条件、分组大小、时延约束、离散速率与固定调度间隔约束的多种分组调度算法，弥补了目前文献中只考虑其中部分约束条件或者部分信息的调度算法的不足。我们通过大量的计算机仿真研究了所提出的各种算法在不同的信道环境中和不同约束条件下的性能，仿真结果证明了本文所提出的几种分组调度算法的性能优于目前文献中一些典型算法的性能，这将为实际系统中分组调度算法的设计提供有益的指导。 为验证、评估本文所提出的各种算法的性能，作者分别编写了容量性能、功率控制算法、接纳控制算法和分组调度算法的仿真软件，并利用这些软件考察了各种算法的性能，本文第六章对这些仿真工作进行了简要总结，并给出了主要的流程图。更多还原

【Abstract】 Future wireless communication systems trend to provide multi-services to mobile users. CDMA technique is adopted by the 3rd generation mobile communication systems due to its flexibility in supporting multi-services. How to keep QoS of heterogeneous services and at the meantime utilize the scarce radio spectrum resources is challenging for 3rd generation mobile communication systems and future personal communication systems, especially in error-prone wireless channel and under the situations of users’ mobility and their interfering with each other. This dissertation studies the capacity performance of the multi-service CDMA cellular systems and three key radio resource management algorithms, which are power control algorithm, admission control algorithm and packet scheduling algorithm.To study the capacity performance of the multi-service CDMA cellular systems is one of the key elements in procedures of the system capacity planning, meanwhile the exact analysis method is helpful to explore the factors affecting the cell capacity and thus remedies can be found to improve the efficiency of the radio spectrum utilization. The capacity performance of both the uplink and downlink are studied in chapter 2. An exact mathematical approximation method is proposed for the uplink capacity analysis, which uses a log-normal distributed random variable to approximate the statistics of total interference signal at the base station. The simulation results demonstrate that the proposed approximation method is more exact than gaussian approximation one , which have been widely used in literature. Computer simulation is used to study the capacity performance of the downlink, as the statistics of the signals received by the mobile users from different base stations is hard to gain. The call arrival process, active factors, wireless propagation environment and power control error are considered in the analysis, and some simplified or idealized assumptions adopted in current literatures are improved to better sketch the characterizations of practical system.HIPower control is one of the key technologies of reducing interference in cellular systems , especially in CDMA systems. An efficient power control method can reduce the interferences between users and increase capacity, for mobile users it also prolongs the working hours of the handsets. The power control problem in multi-service CDMA cellular systems is studied in chapter 3. The concept of generalized SIR balance is proposed firstly, and a class of centralized and distributed power control algorithms which can only be used in single traffic cellular systems are improved to be applied into the multi-service CDMA cellular systems, and thus the system capacity can be increased. Besides, the problem of SIR balance in single traffic cellular systems is proved to be a just a special instance of the generalized SIR balance, thus the theory about the power control algorithms based on SIR balance is supplemented.The cell capacity of CDMA cellular systems is limited, admitting more users than the capacity into system will make the already admitted users suffer a loss of QoS . Call admission control mechanisms must be adopted by the system to protect the QoS of the heterogeneous traffics and at the same time accommodate more users. The problem of call admission control is studied in chapter 4. Two admission control algorithms based on SIR- measurement are proposed firstly and evaluated through extensive simulations under homogeneous and heterogeneous traffic enviroment. The proposed admission algorithms can be used in multi-service CDMA cellular system and make efficient utilization of system capacity, thus make the improvement over the current admission control algorithms based on SIR- measurement which can not support multi-services with heterogeneous QoS requirements.It’s believed that providing Internet-based non-realtime services through packet-switched way can optimize the radio spectrum utilization.In packet-switched networks, proper service disciplines , service ord更多还原