The Research Of Modulation In Communication System Based On SDR

In recent years, with the rapid development of Microelectronics and Digital Signal Processing Technology, more and more wireless functions can be achieved through software programming. So the concept of SDR(Software Defined Radio)comes into being. After lOyears' development, intermediate frequency SDR has already been widely used in both civilian and military systems.The author do some research in detail about modulation techniques based on the SDR Send and Receive platform system. Firstly, the author introduces the basic concepts, structures and research direction of SDR. Secondly, we give some algorithm of the analog and digital modulation that are frequently used in SDR, which including AM, FM, BPSK, DBPSK, QPSK> π/4-QPSK, DQPSK, MSK, GMSK etc.. Then, on the basis of current technical condition, a feasible basic hardware platform is introduced, meanwhile give the method to realize the scheme, finally, on the basis of research on the modulated signal processing algorithm of the Intermediate Frequency, and combined with commonly used modulation way of the mobile communication, we summarize several optimized intermediate frequency algorithms of modulate demodulation ,which is to realize the system. Meanwhile, we provide MATLAB courses and realization of these kinds of modulation, which may play a positive role for the further research in the future.