Symbol synchronization properties of CCSDS turbo codes

The Consultative Committee for Space Data Systems (CCSDS) standards establish a common framework for space telemetry, command and tracking, and covers many applications like deep space and near-Earth missions, Earth exploration, tracking and data relay satellites. In this paper, we present a study on the symbol synchronization properties of the turbo code scheme recently adopted as one of the channel coding options for CCSDS telemetry recommendations. An extensive analysis is presented for transition/symbol probability, run-length distribution and other parameters of key importance for synchronization recovery. All the code rates achievable by the examined turbo code are considered and analysed. We demonstrate that the behaviour of the CCSDS turbo code is generally good, satisfactorily matched with practical requirements, and better than more conventional solutions included in the previous standards. Some critical conditions are also discussed, their meaning interpreted and suitable countermeasures proposed.