Aerospace & Defense Technology - August 2023 - 28

RF & Microwave Technology
Example:NTN Simulation
PathWave System Design, Pathwave Signal Generation, EXATA, WaveJudge
PathWave System Design/STK
NTN 5G Channel Model
PathWave System Design
PathWave Signal Generation
5G Vector Input to PathWave System Design
PathWave Signal Generation
WaveJudge
Decode Showing Doppler & Other
5G Metrics & Message Content
Figure 3. Multi-domain 5G NTN link simulation incorporating satellite kinematics and channel behavior.
ing information signaled in the SIBs)
and Doppler shift. By transmitting with
a pre-correction, it ensures that signals
arrive at the base station with no Doppler
shift. They also arrive with the correct
timing relationship relative to the
base station frame timing.
Digital pre-compensation is a complex
interaction between UEs, satellites, and a
gNodeB. A timing anomaly under specific
conditions can throw off protocol
decoding. Without the right tools, however,
troubleshooting an error can be
extremely difficult. To tackle this chalWorkflow
New
NTN developments should go through the following phases to properly deploy the NTN link
Planning
Software
Modeling
Use software to
model NTN link
Prototype Development/Integration
Implementation
w/ Emulators
Prototype
transceiver
With COTS
Implementation
w/ Real HW
Develop operational
hardware and integrate
in lab/chamber
environment
Deploy
Full-scale
Implementation
Deploy system and
test
Plan/Design/Test/ security throughout the workflow
Security
Figure 4. Virtual engineering speeds 5G NTN development, reduces risk, and improves quality.
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Maintenance
Optimization/
Monitoring
Optimization,
period test, and
monitoring of
systems
lenge, engineers can use simulation to
model and evaluate channel behavior
for a 5G NTN configuration, followed by
emulation for creating prototypes of UE
and gNodeB pre-compensation and
other algorithms.
Early System Discovery and
Exploration
Accurate multi-domain simulation of
a 5G NTN link depends on four elements:
an authentic representation of
complex digital modulation in a 5G
waveform with real-world effects, a complete
model of satellite kinematics,
robust modeling of RF system signal processing,
and a time-correlated view of
5G protocol decoding. Figure 3 depicts a
simulation approach, which combines
RF system electronic design automation
(EDA) and 5G system modeling platforms
to deliver all of those elements.
The RF system simulation tools use the
same measurement science as test and
measurement instrumentation for
equivalent analysis and results in virtual
space. Waveforms and behavioral models
in this simulation incorporate RF system
knowledge, including real-world
effects, with the ability to add new information
from customer measurements.
Using simulation brings early visibility
to potential issues and the ability to
explore design tradeoffs quickly, yielding
valuable insights before evaluating
the PHY layer in earnest.
After system-level simulation of a
ground-based RF system, the next step
would typically be physical prototyping.
An NTN still presents a substantial risk
that prototypes, once launched, would
not be completely reliable and would be
hard to troubleshoot. Even with lower
costs of LEO satellites, any miss in performance
would be expensive in terms of
Aerospace & Defense Technology, August 2023

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Aerospace & Defense Technology - August 2023

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