Abstract:In the first place, the concept and the basic structure, as well as the significance for the development of communication of the software defined radio (SDR) are elaborated. Then, the importance role of the FIR filter as well as the design of the FIR filter based on window-function are introduced , in the mean time, giving the stimulation results. The analysis of the test results show that the design and stimulation by MATLAB is significant for shortening the design cycle, reducing workloads, improving design efficiency.