Portable Vector Signal Generator System Software Development

In the face of test methods and the precision of test equipment, test speed and frequency range for higher requirements and so on, as an important part of test equipment, vector signal software needs to play an important role. Vector signal software should not only meet the requirements of high test speed, high test precision, multi-function, good performance, can also through the development platform of transplantation and the change of the system architecture, reducing the volume of the vector signal generator, convenient to carry.In this thesis, the vector signal software develops from PC to ARM side, using the architecture of ARM + FPGA instead of the traditional architecture of ARM + DSP + FPGA, completing the signal processing through ARM, instead of the traditional function of DSP. The research is mainly focused on the following contents:Firstly, the study of producing the baseband signal. The vector signal software’s most important task is to complete the baseband signal. To generate baseband signal mainly includes producing the data source、signal modulation、sampling and shaping filter. Data source mainly generates pseudorandom code, signal modulation includes the method of PSK, FSK and QAM three categories, software system accomplishes more than 10 kinds of modulation methods of the three major categories. Shaping filter also uses the filters of ascending cosine filter, root ascending cosine filter and gaussian filter.Secondly, this thesis introduces the study of Gaussian channel simulation and graphic display analysis. Gaussian channel simulation is about the signal interferenced by noise. The signal transfers after a gaussian white noise channel, which means the signal transfers after adding fading factors. Doing this Increases the reliability of the software. The graphic display analysis provides constellation figures, vector figures, time domain figures and frequency domain figures. These figures help us observe signal, analyze the characteristics of a baseband signal better. Then this thesis complete software system framework and simulation test through MATLAB.Thirdly, the research of creating graphical interface and development platform transplantation. By means of QT software, creating a graphical interface, which can carry on setting the various parameter in the interface, also convenient to operate, and having a good scalability. Development platform transplantation is that software develops from PC to ARM side, the software program written in the PC migrates to the ARM core board(Exynos4412), to complete the baseband signal generation and analysis verification.Finally, this thesis does the research about the system unity debugging and the software testing. The main content of system unity debugging is to test the communication between the hardware and software, the data of the signal which is generated by the system is sent to the FPGA for storage. By the functional testing and performance testing of the software modules of the software, the thesis verifies the baseband signal and analyzes the signal characteristics through the graphical analysis of the baseband signal. The vector signal generator also meets the requirement of the error vector under 1%, 1% or less of the amplitude error, phase error under 1deg.