【作者】 刘琪；

【导师】 李承恕；

【作者基本信息】 北京交通大学 ， 通信与信息系统， 2009， 博士

【摘要】 复合可重构无线网络(Composite Reconfigurable Wireless Networks)是4G无线移动通信的一个重要发展方向,它的目标是使得异种无线网络之间能够密切合作,充分发挥各自的优势,为用户提供无所不在的无线通信服务。复合可重构无线网络的研究包括两个部分:网络复合与终端可重构。本论文的主要研究内容是终端可重构,即要求用户终端能够根据周围无线通信环境和业务的需求,选择最佳的无线接入网络(RAN:Radio Access Network)和技术,采用软件无线电技术完成自身的重新配置,使得用户能够在任何时间、任何地点实现最佳的无线接入与通信。本论文主要从三个方面对终端可重构展开研究:即通信环境检测、RAN优化选择机制和终端设备重构实现。论文主要工作与创新点有:1.针对可重构终端的无线环境检测问题,提出了基于代价函数的评价标准来实现对信号检测技术的优化选择,并且引入移动代理技术,增强了终端执行环境检测的可行性。2.针对复合网络环境下的无线接入网络选择问题,提出了一种基于三层贝叶斯网络模型的优化选择机制,在原有研究的基础上提高了网络优化选择的准确性和可靠性。3.针对终端的重构控制实现问题,提出了终端重构的分层实现模型,来分步骤地完成终端的各项重构任务,并且通过对终端数字调制/解调的重构建模和仿真,验证了该分层模型的可行性。4.针对复合网络中的频谱共享环境,提出了一种基于跳频的自适应频谱共享机制,设计了终端的干扰避免方案,可有效地避免网间干扰。更多还原

【Abstract】 The concept of composite reconfigurable wireless networks is becoming an important development orientation for the 4G wireless mobile communications in the future.The target of composite reconfigurable wireless networks is that multiple of heterogeneous networks work together.And each wireless network can show its advantages sufficiently,and offset its weakness with the help of other networks. Therefore,the users will get seamless services from heterogeneous networks.There are two parts of research fields in composite reconfigurable wireless networks,i.e.network composition and terminal reconfigurability.The key point of this dissertation is terminal reconfigurability.Firstly,the reconfigurable terminal(RT) should be able to monitor and update the surrounding wireless environment and the service requirements.Secondly,the optimal radio access network(RAN) and radio access technology(RAT) is supposed to be selected for the user.Thirdly,the terminal will be reconfigured based on software defined radio technology.Consequently,the user can connect to the optimal radio access networks and get services at any time and place. In this dissertation,the research on RT includes 3 aspects.They are the monitoring of communication environment,optimized RAN selective mechanisms,and the implementation of device reconfigurations.The main research contents and innovations are as follows.1.RTs’ surrounding monitoring policy:In this policy,a surrounding monitoring -mobile agent platform is put forward,which makes surrounding monitor of RT possible. A scheme based on cost function to select an optimal signal detect method is raised for monitoring RANs.2.RTs’ optimal RAN selection policy:In this policy,a three-level Bayesian network model,which is based on the dual-level Bayesian network model derived from an already published literatuer,is proposed to realize the management function of the RT’s optimal RAN selection.By this model,the RAN selection results are improved.3.RTs’ reconfigurable control and implementation policy:In this policy,alayered model for reconfigurable implementation,which is found on the modular concept of SDR,is brought forward and established.Then,according to rules and demands of this layered model,a reconfigurable implementation model is set up,particularly taking the RTs’ digital modulation and demodulation parts as an example.Finally,the simulation results prove the validity of this policy.4.RTs’ spectrum sharing policy in composite networks:In this policy,a novel adaptive spectrum sharing mechanism based on frequency hopping technology is raised. And interference avoidance(IA) schemes for RTs are designed.By this policy,the interference among different networks is effectively reduced.更多还原