Design Of VDIF Data Encoding Module And Data Preprocessing Module And Corresponding Implementation By FPGA

The Very-Long-Baseline Interferometry is one of radio Interferometry with high angular resolution developed in the late 1960s, and being widely applied in the astronomy subsequently. Now many interface standards have been put out within the these years. These standards reduced the incompatibility within VLBI institute. Now the world is trying to transfer Mark 5B to VDIF, such as Mark 6 system developed by Haystack, which used VDIF. And this is adopted by many VLBI institute.Several Mark 6 have been purchased by our nation to VLBI international united testing and Domestic VLBI terrestrial network. As to every change of data format, it is also to update the data recording device and data playback device . It should have correlator of Mark corresponding to the Mark series recording equipment. Now the software correlator DIFX has been design to support VDIF. Our country is actively study VDIF data frame to use it to next task.So In this paper centers around VLBI, combining the features of VDIF, the main contents and achievements of this dissertation are as follows:1)Firstly, the related theory of VLBI is studied;2)According to the requirements of VLBI Data Transmission System, data encoding module and data preprocessing module that conforms to VDIF data format are studied respectively;3)Put emphasis on the design of data encoding module based on VDIF, and divide this module into basic modules as follows: VDIF data module, VDIF data FIFO, VDIF header module, VDIF header FIFO, data frame control module, data frame FIFO, and output control module;4)Put emphasis on the design of data preprocessing module, and divide this module into basic modules as follows: VDIF strip-head module, VDIF strip-head FIFO , VDIF fan-in module, VDIF cross-switch module and output FIFO;5)Finally, do simulation and verification for these two module.All modules are designed in ISE using VHDL, integrated into one chip and downloaded into the device XC6SLX16-2CSG324. Tests indicate the design function well.