Error correcting codes in telecommand and telemetry for European Space Agency missions: An overview and new perspectives

Error correcting codes have always played a prominent role in the definition of secure and reliable space missions. Both telecommand (TC) and telemetry (TM) have benefited by the introduction of suitable co/decoding schemes, ranging from classic Bose-Chaudhuri-Hocquenghem, Reed-Solomon and convolutional codes to more recent state-of-the art codes based on soft-decision and iterative decoding. As a matter of fact, space TM was one of the first scenarios to propose implementation of the concept of turbo coding that, since twenty years, has traced a new paradigm in the field of error correction. At present the scene is dominated by low-density parity-check codes and these are being progressively included in the design of future missions, in either deep-space or near-Earth scenarios, for the possibility they offer to increase the data rate and/or to reduce the signal-to-noise ratio. The European Space Agency is very active in the field and continuously gives relevant contributions to the standardization activities within the Consultative Committee for Space Data Systems. This paper provides an overview of the error correcting codes included in the current TC and TM recommendations and discusses the new solutions recently proposed in view of most demanding missions, also able to operate in hostile environments like, for example, in the presence of jamming.