Study And Measurement Of The Key Technical Indicators Of GBBF System

It has become the mainstream of the development that communication technology is based on the satellite constellation system, which is to cover the globe and serve for person. In order to reduce the satellite payloads, a GBBF(Ground Based Beam Forming) system is proposed last century, which can win a high reliability and miniaturization by increasing the complexity of the ground station. The key technical indexes of the feeder link of GBBF system will have a great influence on the performance of beamforming. Therefore, this paper studies the technical indexes of the GBBF system based on the continuous wave CDM technology.In this paper, we study the key technical indexes of GBBF feeder link system from the following aspects: 1) An evaluation system of GBBF feeder link is established. Firstly, from the two aspects of the system’s inherent performance and link algorithm performance, a rough index set is constructed which is based on the common index selection principle. Then, the rough set reduction theory is used to reduce the system parameters. Therefore, 5 important technical indexes are obtained. 2) After the establishment of the index set of the GBBF feeder link system, an FIR channel mismatch model is constructed. The performance of the MUSIC algorithm is studied based on it. 3) Test methods of the two indexes of the power leakage and the amplitude and phase of the channel are studied among the 5 important technical indexes. As for the power leakage, a detailed study is described how to use the spectrum analyzer for accurate power measurement method. And for the amplitude and phase test, the measurement method of amplitude and phase based on CDM is studied, and a new amplitude measurement technique based on interpolation is proposed. Compared with the original CDM algorithm, the performance of new algorithm is doubled under SNR of 20 dB. 4) The system platform of the GBBF feeder link test system is presented, and the plan of the PCI-X and Aurora protocol is used for the high speed signal transmission. On this basis, the test of the system is realized by using the software of upper computer.