Research And Implementation Of CORBA Key Technology In Software Radio System

The way of depending on the fixed hardware of radio devices was changed when the concept of the software defined radio(SDR) was proposed. Various functions are realized by using software thought.In order to standardize software radio and improve the portability and reusability, the military of the United States put forward the Software Communication Architecture(SCA) specification, which uses CORBA middleware as the transport mechanism between different components. CORBA plays an important role in software radio system, including shielding the differences of processors, operation system and programming language.With the rapid development of software radio technology, the application of CORBA in SDR faces many problems. On one hand, the performance of most CORBA is not satisfactory, which means the larger transmission delay and low data throughput. The performance of CORBA affects the system transmission efficiency. On the other hand, CORBA doesn’t provide supports to DSP processors, which leads the component on DSP can not interact with component on other processors. In order to solve these problems, the optimization and the support to DSP processors of CORBA are discussed in this paper.First, the technology of SDR and SCA were introduced. Many researches on implementation of CORBA in SCA system were made. At the same time, we analyzed and tested the performance of TAO(The ACE ORB) which is used widely. The main reason leading to larger transmission delay is the process of message handling. Based on this conclusion, many measures were taken to optimize the TAO middleware, such as simplifying the processing procedure and optimizing of redundant bytes of the packets.Second, we made a detailed description about how to implement a CORBA middleware on DSP processors. The shortcomings of MHAL technology were pointed. After analyzing the function requirements on DSP processors about CORBA, we proposed to choose the lightweight CORBA profile in SCA as the design principle. At the same time, we designed different function modules, such as the choosing of transport protocol, encapsulated module and decapsulation module. Morevoer, a IDL-C compiler was designed and implemented, which can translate interfaces defined in IDL language to C language codes.Finally, a test platform was built to validatethe key technology of CORBA implemented in this paper. The results show that the transmission delay of TAO dropped significantly and the performance of TAO were improved. In addition, the component on DSP processor can interact with component on GPP processor by CORBA middleware successfully, which confirmed the validity of DSP CORBA.