SDR Implementation of a Satellite Telecommand Transmitter and Validation using a satellite transponder emulator

This thesis has been carried out within the TT&C (Telemetry Tracking & Ranging) department of Telespazio at the Fucino Space Center. The project focuses on implementing the Commanding functionality of the Baseband Unit (BBU), one of the key components enabling satellite communication. As satellite technology evolves, baseband processing must be upgraded ensuring compatibility with specific satellite communication standards. This result is obtained by combining the National Instrument USRP 2920 device that bridges the analog and digital domains together with the Software Defined Radio (SDR) solution based on the GnuRadio software environment deployed on a general-purpose hardware running Linux OS. The project was structured in two main phases. The preliminary phase involves implementing and testing the CCSDS coding schemes (BCH, LDPC) through Matlab simulations. The obtained Bit Error Rate results have been validated by comparing them with the ones reported in the standard. Secondly, the CCSDS modulation techniques (BPSK, PCM/PSK/PM, PCM/PM/Bi-phase-L) for satellite Commanding purposes are tested using GnuRadio Companion and implementing new signal processing blocks with Python programming language. Finally, with the Metop RF Suitcase testbench, it has been possible to validate the correct implementation of the Commanding functionality. Focusing on the PLOP procedure and the PCM/PM/Biphase- L modulation. The positive result emphasizes the potential benefit of SDR as a cost-effective solution for upgrading the baseband processing. The successful integration of GnuRadio and the USRP platform demonstrates that future upgrades to satellite communications systems can be performed more flexibly and affordably, maintaining compatibility with evolving technologies. Further optimization and testing can provide a reliable and cost-effective alternative to commercially available BBUs.