The objective of the activity is to develop and validate an end-to-end performance simulator for flexible very high throughput satellites embarking active antennas and digital processors. The simulator will assess the payload performance in the far field with real signal excitation and it will focus on the payload architectural and functional performance.
Targeted Improvements: Enabling simulator to support the design, performance assessment and specification of highly flexible payloads, based on functional performance assessment of key payload subsystems (e.g. digital processors, active antennas).
There is a pressing need for High Throughput Satellite (HTS) systems to enhance the flexibility in resource allocation for dynamically assigning bandwidth, time,power andshaping the coverage in line with highly variable traffic demands as well as major operational needs (such as satellite relocation).
The only solution to address these urgent needs is to employ payloads based on DTP/OBP along with active antennas that allow for afully flexible routing of the traffic between beams and between gateways and beams, but also enable on-board digital beamforming. However, simulation tools able to estimate the end-to-end system performance of HTS employing such flexible payloads are either not available or are focused on specific payload subsystems. Hence, the simulation tool to be developed in this activity shall include the functional modelling of:
- Analogue sections of the payload (including RF chains linear and nonlinear distortion plus error distributions).
- Active antennas (including interface with GRASP) and far field emulator scalable up to thousands of active elements.
- Digital/Analogue and hybrid beamforming.
- On-board processor functionalities.
- Payload feeder link front-end for both microwave andoptical options.
The OBP model should include impairments such as:
- Quantization noise of the ADCs/DACs.
- Digital filter non-ideal implementation (finite length impulse responses, finite number of bits for coefficients).
- Fixed point arithmetic.
- Coefficient quantization in the beamforming process.
The tool shall support payload and system architectural and design/specification trade-offsby evaluating the payload performance in the far field with real signal excitation. The payload simulator shall include alibrary oftelecom signals and payload/signal quality evaluation routines for the far-field performance assessment. Unlike other tools, this one shall focus on the payload architectural and functional performance rather than on the detailed modelling of the underlying components. This approach will enable a new payload design paradigm where requirements are apportioned at unit level aiming atrelaxing some key payload parameters to reduce its complexity. For example, key payload parameters that are expected to be substantially relaxed include amplifiers' required compression point (higher compression -> higher efficiency), RF chains differential errors, number ofprocessor ports and number of bits required for signal processing. This end-to-end design and optimisation paradigm mayallow to design competitive very flexible and high throughput payloads with affordable complexity as required by satellite operators. The tool shall include a GUI, allowing the user to draw' the payload and import parameters of each equipment, either based on measurement or modelling.