Future Evolutions

Future Evolutions

Custom signal is an innovative and experimental feature, and evolutions will be planned with first customer’s feedbacks.

Today we already plan to update the feature with the following evolutions to reach our objective to simulate all the legacy signals thanks to the custom signal feature.

FDMA Signals

FDMA signals such as GLONASS G1 and G2 are not managed by the current version of this feature. These signals have the property to use a different central frequency for each satellite vehicle (instead of using a different ranging code). We need to manage this feature in the XML definition file and the shared library.

All Constellations

Currently Custom Signals works with GPS, Galileo and BeiDou. Our objective is to support all the other GNSS constellations: GLONASS, QZSS, NAVIC and SBAS

Complex Signals

In the current version of the custom signal feature many different signals can be generated, but we want to continue to improve the genericity of the feature for 2 reasons:

• With the current custom signal architecture and modulation equation, some signals like Galileo E1 must be generated with 2 custom signal components. We want to have a way to describe modulation functions that can define complex signals such as Galileo E1 or even E5 with only one custom signal component.

• Some legacy signals like GPS L1C (TMBOC(6,1,1/11)) cannot be modulated with the current modulation function. We need a more generic way to describe this function.

The proposed method that will be investigated is to let the user describe this function by directly writing the script that will perform this operation. We will give a way to the user to write the code that will be executed by the graphic card to process all the components of the custom signal. This is possible thanks to a function of the CUDA programming language (used by NVIDIA graphic cards) which is the compilation on runtime.

In that way, the user will be completely free to modulate the collection of subcarriers and codes in the way he wants.

The architecture will look like this: