Design and implementation of CCSDS standards based telecommand system for satellites using VHDL

A Tele-command conveys the information from an originating source (Ground) to a remotely located physical device (Satellite). It has to generate different types of commands which are necessary for various operations of the satellite. In this paper, we explain about the space segment of the Telecommand system using CCSDS standards. The space segment is the receiving end where the commands are received, decoded and distributed to the to the user subsystem for various operations. Coding is used to overcome transmission error introduced by the channel. The Synchronization and Channel Coding Sublayer accepts a stream of channel bits together with information at the receiving end depending on the state of the physical communications channel obtained from the Physical Layer and it performs the functions selected for the mission, and then the transfer frames are delivered to the data link protocol sublayer. So when we transmit the information at sending end, we obtain those information as a valid transfer frames where those are 144 commands of 56 bits each after removing the parity.