Portable Radio Test Platform For Digital Front-end Design And Realization

Radio communication attracts a great deal of attention because it does not need to set up transmission lines, is not restricted by distance, and has good mobility. So it is widely used both in military and civil areas. As the increase of radio communication bands and the applications of advanced digital technologies, the testing of communication equipment is confronted with more and more difficulties.The conventional testing system is constructed of many measuring instruments. These instruments are unwieldy. They are low digital, low modular and low universal. It could hardly be extended and upgraded. So this testing system cannot meet the requirements of communication equipment testing under present conditions.To solve these problems, a portable radio testing platform based on software defined radio is brought out. This testing platform uses digital technologies based on FPGAs and DSPs. It is small, light and has powerful anti-jamming performance. It can realize different functions by loading different software. So this testing platform has good scalability and generality.This paper focuses on the digital front end of portable radio testing platform. The system design of portable radio testing platform and the demand of function and performance for digital front end are introduced first.Then the design and implementation of digital front end based on FPGA are elaborated. This paper designs an intermediate frequency signal processing solution by digital down converting and down sampling to reduce the input data bandwidth of DSP. A compression algorithm is also accomplished to cut down the amount of data and increase sampling signal length. Various data interfaces are implemented on FPGA.Finally a simulator is used to verify the design. According to simulation results, the functions of digital front end meet the requirements of system design.The digital front end designed in this paper is finally applied in portable radio testing platform. This testing platform realizes frequency and power testing of constant frequency signals and frequency hopping signals. It also realizes sensitivity testing of communication equipment. So this paper has certain value in practice.