As part of the IEEE MTT-Sat Challenge the University of Bremen SmallSatGroup investigates in this project an approach of a full-integrated Telemetry and Telecommand (TMTC) unit for spacecraft communication on a software-defined radio (SDR) architecture that is designed with modern system on chip (SoC) technology and state-of-the-art front-end devices. The desired approach, thus, allows an on-demand re-configuration of data processing (e.g., selection of different modulation schemes or coding techniques), as well as RF specifications, such as frequency band selections or sample rate adaption. Those key technologies enables a highly-integrated hardware architecture that is also suitable for small satellite missions, e.g., for low cost cubesat projects.

The University of Bremen SmallSatGroup is a group of students that are enrolled in the master programs “Space Sciences and Technologies”, “Space Engineering”, or “Electrical Engineering and Information Technology” and is guided by members of the Department of Communications Engineering and DLR-Institute of Space Systems. The goal of this group is to investigate techniques for future satellite communication on small satellites.

Today’s spacecraft communications relies mostly on the same architecture as for 10 years. The reason for this is that the conservative space industries still use hardware and technologies that has been used in the past decades, but on the other hand is well known to be reliable under the harsh environment in space. Thus, the performance and efficiency are far away from what can be achieved with state-of-the-art technologies. As an example for digital signal processing, using system on chip (SoC) which compromise FPGA fabrics and high performance digital signal processor designs, allows a higher level of data processing integration into one device and could increase the performance and efficiency of such systems radically. The transfer of this SoC technology to space application such as for the TMTC of spacecraft communication systems has been identify as a role changer and could bring huge benefits with respect to performance enhancement and also allows more flexibility, e.g. for in-orbit reconfiguration capabilities. The SoC hardware can be used to realize a variety of applications with the benefit of very flexible and cost efficient implementations.

In this project, we follow this approach in order to implement a full-integrated TMTC unit for spacecraft communication on a software-defined radio (SDR) platform. The design of the proposed TMTC unit shall be compliant to the Consultative Committee for Space Data Systems (CCSDS) standard and will allow higher flexibility in reconfiguration of the physical layer and data link layer compared to state-of-the-art TMTC architectures. In contrast, common TMTC architectures divide the TMTC data processing on the spacecraft into the radio unit and the on-board-computer (OBC). The radio unit realizes the communication subsystem and is responsible for handling the physical layer, whereas the OBC convers any further data processing from the data link layer up to the application layer. Thus, the proposed full-integrated TMTC unit on a SDR platform is clearly a novel communication architecture for future spacecraft communication. In particular, for the cost efficient design of small satellites this platform will be a key component.

In this phase 1 project, we aim to investigate the principle architecture in order to identify available hardware and software such that recommendations for further development steps can be achieved. To this end, the team is supported by DLR Bremen with its expertise on hardware and software design for space communications.

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