【作者】 陈育斌；

【导师】 李建东；

【作者基本信息】 西安电子科技大学 ， 通信与信息系统， 2000， 博士

【摘要】 Internet和移动通信是近年来通信技术研究的两个热点领域，把数据业务扩展到无线移动环境更加引人瞩目。分组无线网是实现这一目标的理想形式，长期以来在军事和商业领域发挥着重要的作用，被看作未来个人通信系统的重要组成部分。其中，多跳结构的高速分组无线网是一个主要发展方向，也是研究中的重点和难点。 本文深入研究了高速分组无线网理论和技术上的一些关键问题，包括网络低层协议研究、M进制正交码扩频技术的性能分析、高速分组无线网实验系统的设计和实现。主要内容和贡献包括以下几个方面： 第2章研究了高速分组无线网低层协议设计中如何保证数据/话音综合业务的传输问题。通过仿真不同的协议和参数对这两种业务性能的影响，提出一种支持数据/话音综合业务的新网络低层协议。新协议可以在网络业务量较大时满足数据/话音综合业务的不同性能要求，并具有实现简单的特点。 第3章对移动自适应天线应用于多跳分组无线网络终端做了开创性的研究。分析了移动自适应天线方面最新的研究进展，提出把自适应天线技术应用于多跳高速分组无线网移动终端中，深入探讨了应用移动自适应天线对分组无线网可能带来的重大影响。并提出一种基于移动自适应天线的MAC层自适应定向ALOHA协议（AD-ALOHA），和自适应网络协议的设计思想。结果表明，与传统的全向性天线相比，采用移动自适应天线技术和本文提出的协议可极大提高网络性能。 第4章研究了M进制正交码扩频技术在多径衰落信道中的性能。分析了存在同步误差的情况下，采用BPSK调制的M进制正交码扩频信号在多径衰落信道中的相干RAKE接收机性能。分别讨论了不采用分集接收和采用选择式合并、等增益合并、最大比合并等三种分集合并策略时接收信号的误码率，并推导出相应的近似计算方法。在此基础上，分析了不同的分集合并办法、传输参数、码片定时误差和载波相位误差对系统性能的影响。最后仿真了M进制正交码扩频系统的RAKE接收机性能，证明了理论推导的正确性。 第5章提出一种同步信道辅助的M进制正交码扩频系统方案，分别在同相和正交载波上传输同步控制和数据信息。同步信道采用短码扩频，便于实现快速捕获；数据信道采用Walsh函数序列进行多进制扩频。接收机在同步信道解扩获得的定时信息帮助下完成非相干多进制正交码解扩运算。 本文采用最新的扩频、解扩集成电路和大规模可编程逻辑器件CPLD设计了相应的M进制正交码扩频系统发射机和接收机硬件电路，并在中频连接上调试通过。实验结果表明，该系统具有良好的性能。山于本文的电路设计借鉴了可重构的收发信机设计思想，电路具有良好的可扩展能力，增加了网络协议设计的灵活性，并支持向可变速率 CDMA和 RAKE接收技术等方向演变。 第6章采用CPLD设计了接收机电路的核心：M进制最佳非相干正交码解扩单元。首先设计了CPLD的总体结构及各主要模块的电路，提出了三种核心运算单元——多进制并行解扩单元的实现算法：串行FliT法、并行FliT法和并行积分法，并加以比较。结果证明，本文提出的并行相关法可获得计算速度和资源消耗量之间很好的平衡，且具有控制简单、方案灵活、可扩展性强等特点，更适合于高速分组无线网的应用要求，是一种理想的实现算法。更多还原

【Abstract】 Recent progress in Internet and mobile communication technologies has attracted much attention, which leads to an intensive research to extend data services into wireless mobile environment. Packet radio network can provide wireless communication and data distribution among mobile terminals. It plays an important role in military and commercial areas and is interpreted as an integral part of future抯 personal communication systems. The high-speed packet radio network (HSPRN) is critical to meeting the requirements for wide-band, rapidly deployable and robust information systems, studies on which are more challenging. In this dissertation, some of the key technologies in HSPRN are investigated, addressing study on low layer protocols, performance of M-ary orthogonal spread spectrum system, and the experimental system design for HSPRN. The major achievements are outlined as follows. Chapter 2 studies the performance of integrated data/voice services in HSPRN and thoroughly discusses the influence of different low layer protocols on the performance of services and network, on the basis of which some new low layer protocols to support integrated data/voice services are presented. Simulation results show that low layer protocols play an important role in the performance of the network and the protocols presented significantly improve the performance of data/voice integration. Even in case of heavy traffic, these protocols can provide acceptable quality of voice service for a limited number of users. Chapter 3 considers the performance of a multi-hop packet radio network employing adaptive antennas at the mobile stations. A simple adaptive beam-forming policy is presented. In addition, the AD-ALOHA protocol for media access control and the adaptive protocol architecture with adaptive antenna technology are proposed. Analysis and simulation indicates that mobile stations in packet radio networks employing mobile adaptive antennas can offer a significant performance enhancement when compared with their omnidirectional counterparts. Chapter 4 studies the performance of M-ary orthogonal spread spectrum RAKE receivers in multipath fading channel. The expressions for the error probability are derived for BPSK modulated M-ary orthogonal spread spectrum systems employing coherent RAKE receivers in Rayleigh fading channel, which take into account the effect of chip timing error and carrier phase error. Non-diversity and three types of diversity 1? schemes are considered: selection diversity, equal gain diversity combining, and maximal ratio diversity combining. The close-form approximations are derived for the average error probabilities. And the channel characteristics, diversity schemes, and synchronization errors?effects on the performance are discussed. Finally, the computer simulation agrees with the results obtained. A pilot channel aided M-ary orthogonal spread spectrum system for IISPRN is presented in chapter 5, where the synchronization control information is modulated on in-phase carrier and the data information on orthogonal carrier. The data channel is spread by the Walsh-sequences, which can be demodulated under the despread output of the pilot channel spreading by in sequences. In addition, the hardware design of the reconfigurable transceiver for M-ary orthogonal spread spectrum system is presented, employing some new ASICs and更多还原