CCSDS Based Spacecraft Telemetry System with Programmable Bit Rate and Turbo Encoding for India's Inter-planetary Exploration

This paper presents various aspects of CCSDS based satellite telemetry system design and highlights the important development required to cater for Inter-planetary Missions. The various aspects include: Transfer Frame Layer implementation, CRC computation, channel encoding technique (1/2 rate Turbo Encoding for higher coding gain), Randomization, Bit rate programmability (lowering bit rate to augment signal Eb/No for higher orbits), formats (Normal, Dwell and PTM), Data Acquisition (FPGA based), Frame Size, Real-time/Near Real-time acquisition, Acquisition Interface Types (Digital RMU, Analog RMU, Digital bits, RF bits, Digital Word, Analog word, Thermistor), PTM formats (Launch, Early Orbit, Earth bound Maneuvers, Cruise, Interplanetary Orbit Insertion and Payload Operation phases), Command interface, Storage and Playback Interface and Sub-Carrier level modulation, Ground Checkout interface, AIT Interface, Transmitter Interface.