Design And Development Of Frequency-Hopping Communication Waveform Based Of SCA

Software Communication Architecture is a set of standard specifications which was issued by America army in implementing the plan of Joint Tactical Radio System.It provides an implementation independent open framework for the design of Software Defined Radio. The central idea of Software Communication Architecture is using the object-oriented way to design a standard software system.To load different software waveform into common hardware platform can achieve different functions,so that wireless radio can be easily upgraded by changing the software waveform. This not only achieves the goal of software reusability but also shortens the development cycle and cost.The specification of Software Communication Architecture defines hardware architecture, software architecture,security architecture and application programming interface (API),these correspond to development of hardware platform,software framework and waveform,security system.Software architecture not only divides the software system into Bus layer,Network and Service interface layer,Embedded Operating System layer,Common Object Request Broker Architecture middleware layer(CORBA),Core Framework layer and Application layer,but also issues the ideas of waveform and waveform development.Waveform is a carrier which can achieve different functions and a communication function points to a waveform.Waveform development is the realization process of communication function into software and this reflects to the central idea of software reusability.By analyzing function of each software architecture layer in Software Communication Architecture and the guide of waveform development,this paper gave the procedure of software waveform development and chose Frequency-Hopping communication which was the important technology in wireless communication as the original model to develop waveform.This paper first described working principle and key technology of frequency hopping system, such as frequency synthesis,PN code generation, time synchronization.This paved for analysis of waveform function and component division.And then the paper analyzed the advantage of frequency hopping,which was the significance of waveform development.The two important technologies CORBA middleware and UML modeling were also described for detail.Based of the waveform function,paper divided the waveform into Physical layer,Medium Access Control layer, Logical Link Control layer and I/O layer.As a well-known software tool,Rational Rose was used to design the API of these components with Unified Modeling Language idea.And also with the help of Rational Rose,the models were mapped into Interface Definition Language (IDL) which could make sure that the interfaces of components were standardized,so that the goal of interoperation and intercommunication between different components were achieved.Then paper compiled the components'IDL into C++ code framework using the technology of middleware,such as VisiBroker.By adding implementation program into the C++ framework and operating with the variables and functions in the classes,the function of components was connected and frequency hopping waveform was developed successfully.At last paper described how to load the waveform into operating system through center framework.In order to solve the security problems when loading waveforms,paper designed an encrypted sub-system based of Security Specification in Software Communication Architecture. The developed frequency hopping waveform agreed to the characters of generality and reusability of Software Communication Architecture,and the frequency hopping function was achieved after loading waveform into wireless radio as software.