STK COMMUNICATIONSThe Communications module is used to model andanalyze real-world RF and optical communications.

Provides high fidelity modeling andanalysis that includes:• Detailed link budget reports andgraphs• Signal performance contours• Visualization of dynamic system
performance• Detailed rain models, atmosphericlosses, and RF interference sources• Ability to plug in custom models orinterference sources• All system models easily editable fromthe components browser

System modeling
Provides the ability to model thephysical components of each node in
any communications system.
• Eight STK receiver types: Simple,Cable, Medium, Complex, Multibeam,Laser, RF plugin, and Laser plugin• Eight transmitter types: Simple, Cable,Medium, Complex, Multibeam, Plugin,Laser, and GPS Satellite• Three re-transmitter models: Simple,Medium, and Complex• Over 60 Antenna types, including
multi-beam and phased array• Over 20 power spectrum filter models
for a transmitter or receiver• Wideband and narrowband jammer
modulators, third-party modulators,
external file modulators, and script
plugin modulators• Multiple demodulators, including auser-defined demodulator

Multi-beam antennas• Each beam is an independent antenna
with its own frequency, RF power
level, polarization state, gain andcharacteristic type.

• Each beam’s boresight directions canalso be independently oriented.
• Aggregate contours are displayed in
2D and 3D.
• Variable beam selection criteria.
• Different beam selection criteria,such as maximum gain or minimum
boresight angle, or plugin script.

Phased array antennas• Multiple element configurations:
Circular, Hexagon, Linear, Polygon,
and external data.
• Define number of elements andspacing.
• Disable/enable individual elements.
• Specify beam direction and Nullsteering to other STK objects from adata file or script.
• Adaption algorithms include Min.
Variance Distortionless Response(MVDR) and user specific weights froma data file or script.

Modeling the RF environment
A full range of environment models isprovided.
• Empirical rain models: Crane 1982,
Crane 1985, and ITU-R P.618-20,
as well as user-definable outage
percentage and rain rate.
• Atmospheric absorption models:
ITU-R P.676-9 and Simple Satcom.
ITU-R P1814 for laser receivers.
• Urban and terrestrial models: Two-Rayand STK Urban Propagation extension.
• Clouds and fog models: ITU-R P.840-3
recommended for attenuation due toclouds and fog• Tropospheric scintillation model: ITU-R
P.618 model with option to computedeep fade• Custom loss plugin models• Object specific losses such as local
surface atmosphere and systemtemperature• Terrain Integrated Rough Earth Model(TIREM)

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STK COMMUNICATIONS
Terrain Integrated RoughEarth Model (TIREM)TIREM adds fidelity to the calculationand dynamic modeling of point-topoint, line-of-sight effects for linkperformance in Communications, bytaking into account the effect of irregularterrain, sea water, and non-line-of-sighteffects. The maximum height for thesemodels is 30km.

Analyzing comm systems
The full power of STK reporting andgraphing is available to present analysesof communications links.
Link margin specification andcalculations• The Link Information report for aReceiver includes the Link Margin
Type (BER, RIP, C/N, etc.), Link Margin
threshold value,
and the computed Link Margin.
• Report results can be filtered based on
the Link Margin calculation.
Interference analysisConstraining RF phenomenon
Communications links can beconstrained in a variety of ways on atransmitter or receiver.
• Frequency range, received isotropic
power level, power flux density, link
EIRP, Doppler shift, carrier-to-noise
density ratio, power at receiver input,
true carrier-to-noise ratio, bit errorrate, link margin, bit energy to noise
power density ratio• Relative angle between thetransmitter’s plane of polarization andthe receiver’s plane of polarization• Dynamically computed ratio of the linkbudget receiver gain value (G) along
the link vector and the total receivernoise temperature (T)• User plugin• Performs network and target
interference analysis as well as
target interference analysis.
• Quickly calculates the impactof the interference network into
communication links and presents
the results as time-ordered data andstatistical summaries using probability
density functions (PDFs) andcumulative density functions (CDFs).
• Enables you to investigate the C/(N+I),
C/I, DT/T and power flux density.
• Interference analysis for a specificlink (e.g., ground station to a target)
can be accomplished quickly byleveraging the STK Satellite Database.
• Combined with a user-supplied RFI
database file, you can quickly identify
which satellite may cause or besusceptible to RF interference from aground station.

Fully integrated withSTK analysis tools
STK Analysis Workbench tools. Extend
the fundamental computational
capabilities of Communications byusing the Time, Vector Geometry, andCalculation Tools. (Requires Pro andAnalysis Workbench licenses.)
Coverage and Volumetric analysis.
Evaluate spatial conditions andcalculations across a number of gridpoints. (Requires Coverage and Analysis
Workbench licenses.)
Coverage or SatPro. Display jamming/
interference contours on 3D coverage
grids or on the 3D attitude sphere. You
can also investigate the C/(N+I), C/I,
DT/T and power flux density.

Integration with third party
tools

Visualize and animate youranalysis

Connect and Object Model. Automate
and interface custom software using
the Connect engineering-level interface
or the finer grain MS Com-compliant
Object model interface.

Highlights the Communications
components, such as interferers, during
the STK animation period on both the2D map and 3D globe.

MATLAB. Generate link budget databetween a transmitter and a receiverthat is suitable for the STK MATLABinterface.
QualNet interface. Combines network
performance evaluation from QualNet
with the platform mobility models,
wireless link calculations and mission
visualization environment of STK.

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