| Signal Simulation
Tool
The MATLAB Signal Simulation Tool simulates the effect of
the GPS satellite signals on a conventional GPS receiver's
code and carrier tracking loops. The Toolbox’s GPS signal
processing simulation architecture includes a truth profile.
This truth profile is used to generate the simulated GPS signals
as a function of the signal strength, pseudo-range, Doppler,
and Doppler-rate. The receiver profile defines the receiver
being simulated, and the parameters used by the receiver to
process the GPS signals. The state output from the simulated
receiver models the output from an actual GPS receiver experiencing
the simulated conditions. The signal simulation tool can be
used as an analysis aid to assist in test and evaluation of
GPS receivers beyond the capability of conventional RF signal
simulators that do not provide low-level insight into the
operation of a GPS receiver. This insight can in turn be used
to specify key parameters for receivers to optimize their
performance in the presence of perturbed GPS environments.
Geographical Tools
The Toolbox’s geographic tools facilitate the transformation
of data between the various coordinate systems commonly used
in GPS research, such as latitude-longitude-altitude, WGS-84
ECEF, North-East-Down, and body reference frames. These tools
provide the user flexibility in data representation.
Satellite Geometry Tools
The Toolbox also provides tools to read GPS almanacs and ephemeredes
and compute ECEF and line-of-sight vectors to GPS satellites
as a function of user position and time. The tools can also
compute GPS dilution of precision (DOP) values and determine
predicted GPS satellite visibility.
Receiver Design and Analysis Tools
The receiver design and analysis tools model different receiver
architectures and simulate different error scenarios. With
these tools, a simulation can predict how a receiver will
react in different environments, such as urban environments;
environments susceptible to multi-path effects; and high-dynamic
situations.
The signal simulation flow diagram executed when generating
a simulation profile is illustrated below. This can be used
to generate simulated data sets for playback and analysis
by the built in receiver module within the MATLAB tools. The
simulated GPS signals can also be played back into a GPS receiver
under test as live digital or RF signals using our Advanced
Hybrid Signal Simulator (AGHS) product. |
|
|
For
more info, contact