PAGE CONTENTS
Objectives
The objective of this activity is to evaluate the potential benefit of OGB compared to OBB in terms of complexity, power, cost and performances for missions with a high number of spot beams like Mobile Satellite Systems.
- The particular requirements and challenges for both OGB and OBB techniques are analysed and compared for several mission and system scenarios. Particular focus is put on the definition and analysis of OGB system through the assessment of its applicability to mission scenarios derived from satellite operator needs.
- The selected solutions are the basis for the definition of a technology roadmap for the European industries.
The study includes also additional tasks in liaison with an Artes 5.1 study on Ground beamforming proof of concept test bed. The objective of these additional tasks is to evaluate the test bed results, and to elaborate on its performance through simulation of a complete satellite system employing OGB fixed beamforming approach.
Challenges
Some assets of on-ground beamforming techniques have been highlighted by new existing systems in particular dynamic and adaptive ground-based beamforming as well as interference suppression capabilities (adaptation and real time pattern control).
On the other hand a larger feeder link bandwidth is needed and additional calibrations functions are to be implemented.
Moving the beamforming processing from the payload to the ground imply some savings at payload level but it has to be balanced by the additional on-board calibration requirements, improved payload phase noise and stability performances.
It is thus of particular importance to evaluate the potential benefit of On-Ground Beamforming compared to on-board beamforming in terms of complexity/mass/power and cost for Mobile Satellite Systems missions.
Plan
The work is sequenced in five tasks:
- Survey of OGB/OBB techniques and technologies
- State-of-the-art
- Review of current systems
- Definition of reference mission scenarios
- Interview of Satellite Operators
- Mission Definition
- System Requirement Definition
- Evaluation Criteria Definition
- Space/Ground Architectures Trade-offs
- On-Ground Signal Processing
- Beamforming Calibration
- Preliminary Design Definition
- Beamforming Impairments Analysis
- Feeder Link Bandwidth Reduction
- System Performance Assessment
- System Design Consolidation
- Software Development and Validation
- Performance Assessment and Analysis
- Technology Roadmap and Recommendations
- Ground Technology Roadmap
- Space Technology Roadmap
Current Status
The study, including the CCN activities, is now completed with the following achievements :
– Survey of the literature and patents dealing with OGB architecture and investigation of the current systems implementing OGB (TDRSS, ICO G1, Terrestar, Skyterra)
– Selection of two scenarios of main interest for the task of mission definition:
– Architecture trade-offs .
– S and L-band missions’ consolidation and performances assessment through software tool simulations.
– Key technological developments roadmap to ensure European industry competitiveness in the strategic field of MSS
– Analysis of the results of a test bed (carried out in the frame of another Artes 5.1 Study)
