Teledyne Paradise - Signal-Under-Carrier Interference Detection - Richard Horner

1. Commercial-in-Confidence
Teledyne Paradise Datacom
LinkGuard™ Signal-under-Carrier
Interference Detection
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Richard Horner
Commercial Director, Latin America

2. Commercial-in-Confidence
LinkGuard™ Interference Detection
• Paradise modems support the world’s leading
set of web-based link diagnostic tools:
• Time-based performance graphs (Eb/No, etc.)
• Spectrum monitor, BER tester,
• Constellation monitor, and now…
• Signal-under-carrier interference detection

3. Commercial-in-Confidence
LinkGuard™ Applications
• Detects:
• Other modulated carriers transmitted on the
wrong frequency
• Adjacent satellite, adjacent channel, or
cross-pol interfering carriers
• Amplifier intermodulation products
• Terrestrial interference
• Wi-MAX
• Radars
• Self-interference from faulty RF equipment
(spurs and spikes)
• Jammers (purposeful interference)

4. Commercial-in-Confidence
LinkGuard™ Implementation
• Patented DSP algorithm running on the modem
processor
• Demodulator output is remodulated (but not transmitted)
to allow comparison with the raw received signal
• The remodulated signal attempts to match the
demodulator input in terms of
• Filtering characteristics, amplitude, phase, frequency
offset, sample rate and time difference
• The remodulated synthesized signal is subtracted from
the received signal to identify any signal under the
demodulated carrier
• FFT is performed on both the demodulated carrier and
the residual signal in order to display both as power
spectra

5. Commercial-in-Confidence
LinkGuard™ Key Features
• Signal-under-carrier spectrum graph
• Fast Fourier Transform, high resolution
• Resolution = Carrier bandwidth / 2048 samples
• ‘Persistence’ mode
• Spectrum builds up over time capturing even
temporary interference
• Captures interference above carrier as well!
• Compatible with PCMA
• Can view any interference underneath the
received carrier following Paired Carrier signal
cancellation

6. Commercial-in-Confidence
LinkGuard™ Example
• 10Mbps 32APSK carrier – no interferer!
• Rate 0.828, Eb/No = 14.5dB, Es/No = 20dB

7. Commercial-in-Confidence
LinkGuard™ Example
• Same carrier but now with interferer!
• Interferer is 500kbps, QPSK rate ½
• No visible degradation to carrier even
though link Es/No degraded by 4dB!

8. Commercial-in-Confidence
LinkGuard™ Key Features
• User-configurable interference alarm
• Can set power threshold for interferer
• Modem generates alarm above threshold
• Proactive 24x7 monitoring
• Interference detection is active even when
not viewing web graph
• Operator not required
• Works while on traffic
• Available in every Paradise modem

9. Commercial-in-Confidence
LinkGuard™ Benefits
• Unlike traditional interference detection
equipment
• Every carrier everywhere is monitored at all
times
• Monitoring is proactive, not just when you
suspect you have interference
• Is truly affordable (currently free with each
new modem)
• Interference status information can be
retrieved remotely
• ‘Over the air’, via internet, LAN, SNMP, etc.

10. Commercial-in-Confidence
LinkGuard™ Summary
• New ‘first line of defense’ against
interference
• Quicker interference detection leads to
• Protection of service revenues (and service
provider’s reputation)
• Less service downtime/degradation
• Lower maintenance costs
• Helps resolve SLA quality-of-service disputes
• Paradise patent-pending technology
• Not available from any other modem
manufacturer

11. Commercial-in-Confidence
Obrigado!
Richard Horner
rhorner@teledyne.com
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