Research And Implementation Of Inter-ratinteroperability In TD-LTE Multimode Termination

TD-LTE is the long term evolution of TD-SCDMA technology and a newgeneration of broadband mobile communication technology, which is dominated byChina. In various aspects of the system bandwidth and data transmission rate hassignificantly improved than the TD-SCDMA system.Most of the mobile operatorsare limited by the large cost and long cycle of the wireless network construction andother difficulties, the current TD-LTE is still only in the period of rapid development,that can not achieve a large-scale coverage within a certain time. But now, forTD-SCDMA and GSM system, in contrast, the network construction has been verymature, and achieved a large-scale national coverage. That can offer an effectivesupplement and improvement to the TD-LTE networks. The2G,3G,4G networkswill coexist in a very long period of time. How to implement a terminal compatiblewith a variety of networks, multimode chips and solutions will be the only way, andthe protocol of multimode terminal communication system only defines thenecessary configuration parameters and requirements without uniform standards ofimplement. Thus，how to plan the compatibility between every mode, optimize theinteroperability，share physical resources, and design software architecture, is theproblem that the terminal physical developers have to consider.How to implement aterminal compatible with a variety of networks, multimode chips and solutions willbe the only way, and multimode terminal communication system in the agreementonly defines the necessary configuration parameters and requirements, no unifiedstandard of implement, thus if the compatibility between every mode and planning,optimization of interoperability and sharing physical resources, software architecturedesign, is the problems that the terminal physical developers must conside.Based on a detailed study of TD-LTE, TD-SCDMA, GSM physical layerprotocols, further to between TD-LTE multimode terminal systems interoperabletechnologies were studied. For can not be extended,the high degree of coupling andother issues of the existing physical layer software architecture, this paper presenteda kind of physical layer software architecture in multi-mode terminals that can beextended and get low coupling, then studied and did the process design focusing on the cell re-election, cell handover between the systems. Finally, this paper simulatedand implemented the related contents about the inter-RAT measurement. The mainwork and innovation of this paper is as follows:1, Studied and compared the differences between TD-LTE, TD-SCDMA, GSMthree modes of the system architecture and the physical layer technology, from apractical description of the need for interoperability between systems.2, The TD-LTE inter-system measurements, carried out between modeconversion study and research on this basis, for TD-LTE multi-mode terminalphysical layer software architecture and module design, its simple structure, modeThere is no direct interaction between, so support for multi-mode multi-card isbetter than other architectures.3, The proposed scalable multi-mode handset implementations, and in thisscenario, the system of inter measuring system re-election, inter-system handoverbetween systems interoperable content to do a detailed implementation processdesign.4, Using the relevant instruments, terminal boards and programmable devicesbuilt hardware platform, and the preparation of the relevant program code, thecontents of the inter-mode measurements do the actual verification, test resultsobtained to verify the validity of the research content.