The main objectives of the project is to develop a detailed simulation tool for complex RF payload front-ends within a system simulator.
The tool has to allow to:
In particular, the tool allows for a detailed modelling of various antenna architectures and associated beam-forming networks (e.g. active, semi-active), in combination with the rest of payload. Traditional design approaches typically address the performance assessment for the antenna system separately from that of other payload elements of the RF front-end.
During the project, a few complex RF-front-end architectures (featuring either Single-Feed-Per-Beam Antennas, or Array Fed Reflectors Antennas or Direct Radiating Array Antennas) were defined for SW validation purposes.
The tool is a time-domain waveform simulator able to evaluate the payload impact on the end-to-end signal degradation and on the overall system performance. Time-domain simulation of signal waveforms traversing the whole payload, including antennas (characterized through their far-field radiation properties) is performed.
The tool is able to evaluate the end-to-end effects of the payload on digital signals in terms of FER/BER, including the effects of antenna and advanced front-end architectures (e.g. active antennas, MPAs, etc.). In alternative to FER/BER evaluation the tool is able to evaluate SNIR degradation due to the payload (antenna included) which may shorten simulation time in some conditions.
The payload simulation tool provides an efficient interface with complementary external tools (e.g. antenna tools) to generate the Far Field Electromagnetic channel matrix covering the interesting ground area and considering all the elements (beams or feeds) of the considered antenna.
The validation process of tool, done using real measured data from different defined RF-front-end and antenna architectures, was very successful and encourages the use of the tool in real complex payload projects.
In fact the very rich set of building blocks library has allowed to easily implement and verify the selected reference payload architectures, i.e.:
The Payload Simulation Tool (PST) for Complex RF-Front-End software is structured in layers, so to maximize the modularity and the scalability of the tool.
The simulator engine is based on Space Engineering’s Physical Layer Simulator (LiveWave), developed for the ESTEC Contract No. 18070/04/NL/US. LiveWave is a Waveform-level simulator, developed in C++ and entirely based on Windows COM components. The provided library of building blocks have been deeply upgraded and modified to meet the requirements of the new payload tool and extended with the ability to interface with MATLAB/Simulink.
The Graphic user interface (GUI) of the tool allows to:
A simulation is performed adding and connecting several building blocks in the GUI according to the needed simulation topology.
The GUI converts the scenario in a script and starts the underlying simulation engine that executes the generated script. It is worth to note that the GUI and the simulation engine are independent to allow a seamless updating and upgrading of the simulator engine.
The provided Building Blocks can be classified in:
The payload simulation tool SW runs on any Microsoft Windows OS (XP or newer).
The project plan is divided into the following phases:
The project was completed in May 2012.
The final conclusions are: