Design of a data playback module for Very Long Baseline Interferometry

With the development of VLBI technology, the correlator system of observation station is constantly upgrading, so as to adapt to new data format and higher processing speed. Now the conversion of data format from Mark 5B to VDIF has been built by the researchers around the world. Once completed, it will be conducive to VLBI international collaboration. Hence it is very meaningful to study the VDIF. In VLBI system, data preprocessing must be completed by the VLBI data playback module before correlation. In this paper, a new design for a VLBI data playback module is proposed and corresponding simulations are performed to verify the results.