Software Design And Related Technology Research Of Baseband Signal Generator

The baseband signal generator plays a key role in the normal operation of the vector signal source.It is an indispensable component module.During the working process,the digital modulation baseband signal can be generated and directly output to the output of the communication system.However,the traditional baseband signal generator has been difficult to meet the needs of rapidly developing communication technologies.Therefore,it is very important to improve the digital baseband signal generation technology.Through a series of improved technologies,a new type of baseband signal generator is developed.The generation of digitally modulated baseband signals with a variety of different formats and large bandwidth ranges can drive the development of modern communication technologies.In this study,the baseband signal generator is selected as the key research object.In view of the shortcomings in the current field,a new digital baseband signal generation scheme is designed by using FPGA technology.At the same time,the vector modulation technology and programmable logic device are comprehensively developed.A versatile hardware platform that exhibits openness,standardization,and modularity.This study focused on the baseband signal generator,using FPGA platform to test multiple modules,and combined with PSK,FSK and QAM digital modulation baseband signal characteristics to effectively complete the I / Q real-time baseband function.This research focuses on the in-depth analysis of signal transmission techniques in digital baseband signals,such as high-speed digital shaping filtering,variable interpolation filtering,and direct digital frequency synthesis.Through deep testing,it is found that the digitally modulated baseband signal generated by the baseband signal generator can simultaneously use several modulation formats such as FSK,PSK,and QAM,and achieves good results,which fully complies with relevant design standards.The conclusions of this study can be summarized as follows:(1)Design of baseband data in a multi-standard format environment,implementing BPSK,QPSK,OQPSK,DQPSK,Pi/4QPSK,3Pi/8-8PSK,8PSK,16 PSK,2FSK,4FSK,8FSK,16 FSK,MSK,GMSK,4QAM,16 QAM,32QAM,64 QAM,128QAM,256 QAM,512QAM and user-defined modulation format baseband signal generation technology and arbitrary wave signal generation technology.(2)The baseband data source design was completed,and ALL1 s,ALL0s,PN9,PN13,PN15,PN23 and the baseband data required for this research were designed.(3)According to the research requirements,a multi-system filter is designed.The filter can adapt to three variations of cosine,Gaussian and root-raised cosine,so that real-time filtering can be realized effectively.(4)It is designed to adapt to the changing interpolation filter,which can effectively improve the symbol rate of a large area,and can change in the interval 1kSym/s to50MSym/s.When the DA fixed clock is 200 MHz,it is realized.The symbol rate is 1kSym/s to 50 MSym/s variable with a resolution of 1 Hz.