The Design And Implementation Of Communication System Based On Software Defined Radio

With the rapid development of wireless communication technology, various communication system and communication equipment appear constantly, the traditional wireless communication equipment cannot meet the actual communication demands gradually due to its single function and poor expansibility. The emergence of software defined radio technology points out the direction of the solution to this problem. Software defined radio proposes a new thought of design, manufacture and usage of the wireless communication system. The system does not rely on the fixed hardware by using modular general hardware platform. Software defined radio has the advantages of software programmable, good interoperability, versatility and low cost. In the development method based on software defined radio, the FPGA is widely adopted because of its advantages of flexibility and high performance. Nevertheless, in order to implement the FPGA development, the designer not only needs to be familiar with hardware description language but also should have a grasp of hardware. However, graphical System Generator module library can increase the development efficiency greatly.On the basis of the research on software defined radio technology, this paper designs and implements a communication system according to the specific application scenario and functional requirements. The system realizes the function of text message interaction and file transmission via a wireless link between two terminals. This paper mainly studies the scheme of system design and implementation of the physical link. It proposes the design of baseband signal processing, including coding, modulation, spread spectrum, time synchronization and equalization, as well as digital up and down converter based on SDR platform and System Generator module library. Finally, the experiment link model is constructed in the development environment, the results of simulation and experiment test show that the system can meet the functional requirements.