Impact of Error-Correcting Code Performance on Telecommand Rejection in Ground-to-Space Communications

In space missions, particularly deep space ones, one of the key needs is to establish a link with the satellite, even during the safe and survival modes, in order to maintain the capabilities to send TeleCommands (TCs) to the satellite and to receive Housekeeping TeleMetries (TMs) from the satellite. In current deep space missions, such as BepiColombo, TCs are typically encoded by the Bose-Chaudhuri-Hocquenghem (BCH) code specified in the Consultative Committee for Space Data Systems (CCSDS). However, for upcoming deep space missions still in the development phase, short Low-Density Parity-Check (LDPC) codes (also standardized by the CCSDS), with length 128 or 512 bits and coding rate 1/ 2, are being considered alongside the BCH code. Since the goal is to introduce minimal changes to the existing ground systems, it is necessary to evaluate system performance when the LDPC codes are used in place of the BCH code currently implemented. This paper first focuses on the analysis of the application of a (128, 64) LDPC code in the current configuration. Then, we provide an overview of alternative configurations and compare the performance of the system when using the (63, 56) BCH code, the (128, 64) LDPC code and the (512, 256) LDPC code.