Research On Terminal Reconfigurability In Composite Reconfigurable Wireless Networks

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.