LS telcom AG · XETR:LSX
LS telcom — Narda Safety Test Solutions — LS Summit 2014
31 slides from LS telcom's conference presentation, Jul 2, 2014
Slide 1: New test methods for efficient on-site detection of in-band interferers
15:45-16:15 Lichtenau, 2nd July 2014 New test methods for efficient on-site detection of in-band interferers - a real-life case study: hunting disturbers in UVHF band Volker Brands, Narda Safety Test Solutions GmbH, Germany
Slide 2: Spectrum Inventory: Knowing the real use of spectrum resource
Spectrum Inventory : Knowing the real use of spectrum resource and making most out of it ! Excerpt: Spectrum is a scarce resource - hence allocated bands must offer error- free transmission of services. Interference-free channel is the prerequisite of high-quality transmission. As interference hunti
Slide 3: Case Study: Disruption of VHF Reception
Case Study : Disruption of VHF Reception Two FM radio stations affected › Continuous interference issues were reported in the 100 MHz range (SWR3 & Deutschlandradio Kultur) from a street (Große Heerstrasse) in Pfullingen (Swabia city), during autumn 2013 › After an initial site survey shadowing effe
Slide 4: Gapless Persistence Display unveiling Transients
Gapless Persistence Display unveiling Transients 3
Slide 5: Detection of a sporadic variable frequency Interference between 99 …. 101 MHz
Detection of a sporadic variable frequency Interference between 99 …. 101 MHz However following spectral lines are stable › SWR3: Hornisgrinde 98.4 MHz › Deutschlandradio Kultur: Tübingen 99.4 MHz › Radio Regenbogen: Hornisgrinde 100.4 MHz › Hit-Radio Antenne 1: Stuttgart / Frauenkopf 101.3 MHz 4
Slide 6: Gapless Spectrogram identifies Interferer based on correct Correlation of Frequency with Time
Gapless Spectrogram identifies Interferer based on correct Correlation of Frequency with Time 5
Slide 7: Further Pinning down Characteristics of Interferer
Further Pinning down Characteristics of Interferer Findings from gapless spectrogram › Interferer occurs about every 4 ms › Interferer ‘sweeps’ thru a band of some 2 MHz within 1 ms › This signal identification and classification will help to finally assess root cause …. › Furthermore it ensures tha
Slide 8: Next Step: Prepare for DF of Interferer
Next Step: Prepare for DF of Interferer Considerations › Distance to Interferer ? › Multi-path propagation / reflections / shadowing ? › Broadcast signal level is of same magnitude as Interferer › However when moving from that particular spot the interfering signal is becoming strongly attenuated ›
Slide 9: Horizontal Scan offering numerous bearings - 360°
Horizontal Scan offering numerous bearings - 360° 8
Slide 10: Two to three Bearings needed for Triangulation
Two to three Bearings needed for Triangulation Triangulation will narrow down location of emitter › Triangulation from two Horizontal Scans indicates the apartment block on the opposite side of the street: intersection point › Area can be narrowed down to just a few houses › Further bearing taken fr
Slide 11: Triangulations from two different blocks
Triangulations from two different blocks 10
Slide 12: Third Bearing taken from courtyard reconfirming results
Third Bearing taken from courtyard reconfirming results 11
Slide 13: 'Last Meter' finding by Checking for max. Level
‘Last Meter’ finding by Checking for max. Level 12
Slide 14: Interferer was found in next to no time …
Interferer was found in next to no time … A simple radio clock turned out to be source of interference …. › After replacing of defective alarm radio by a new one further investigations were made in the lab. › A defective PLL (phase locked loop) in the VHF receiver caused excessive emission in that c
Slide 15: Interferer shown in classical (sweeping) Spectrum Analysis
Interferer shown in classical (sweeping) Spectrum Analysis 14
Slide 16: … and in classical (sweeping) Spectrogram Display
… and in classical (sweeping) Spectrogram Display 15
Slide 17: Scope mode shows Time Characteristic of Interferer
Scope mode shows Time Characteristic of Interferer 16
Slide 18: What is the Algorithm behind gapless analysis?
What is the Algorithm behind gapless analysis ? IQ Data Streaming of demodulated base band signal offers … › Gapless IQ data recording, either separate I (real) and Q (imaginary) vector information and presentation of magnitude in Scope Mode: time domain display with 32 ns resolution and CBW of 100
Slide 19: Gapless Analysis based on real-time RAW Data Acquisition
Gapless Analysis based on real-time RAW Data Acquisition
Slide 20: IQ Data Processing for Persistence Spectrum
IQ Data Processing for Persistence Spectrum 19
Slide 21: IQ Data Processing for HiRes Spectrogram
IQ Data Processing for HiRes Spectrogram 20
Slide 22: Further Sources of RF Interferences
Further Sources of RF Interferences Challenges to address … › Wireless micros & video cams, illegal jammers, electronic devices, etc. › Unmaintained or defect boosters / repeaters (BDA) leading to oscillation › Cable leakage (egress): VDSL vs. PLC and LTE vs. DVB-C, etc. › Fluorescent light, switchi
Slide 23: DAB+ In-Band Interferer Detection
DAB+ In-Band Interferer Detection 22
Slide 24: GSM900 UL Jammer Emission outside of a Prison
GSM900 UL Jammer Emission outside of a Prison 23
Slide 25: Latest Trends in RF Testing
Latest Trends in RF Testing Over-the-air (OTA) testing – on site ! › Upcoming fiber-fed remote radio heads (eNBs) offering no more electrical sniffer ports for SA - hence growing demand for OTA test › Modulations methods are increasingly digital, and respective interferences, too – hence time domain
Slide 26: Upcoming Signal & Interferer Data Base
Upcoming Signal & Interferer Data Base For your easy & ready reference …. › Narda will soon prepare an expert’s tool on https://www.narda-sts.com/en › If you would provide us your business card, then we will be glad to notify you, soon 25
Slide 27: Thanks for your attention!
Thanks for your attention ! Questions ? › Otherwise we may recap : › Important receiver performance › What is significance of 100% P.O.I. in sub ns range ? › Who & What is Narda ? 26
Slide 28: Receiver Performance acc. to ITU-R SM.1837 …
Receiver Performance acc. to ITU-R SM.1837 … Requirements … … to fulfill high demand of RF interference & DF › Wide intermodulation free dynamic range › Good IP3 / IP2 values & lowest spurious › Good noise factor & phase noise › High-dynamic, low noise pre-amp, wide input attenuation range with smal
Slide 29: 100% Probability of Intercept
100% Probability of Intercept 100% P.O.I. - even for single ns pulse › Minimum event duration for 100% P.O.I. down to ns range Time Domain Magnitude › Trigger on Interferer for IQ recording offering further in-depth analysis › Pulses > 30 ns shown without drop of amplitude HiRes Spectrogram HiRes Pe
Slide 30: What Narda offers …
What Narda offers … Diverse Know-How in RF Technology › Global market leader in field strength test & measurement as well as in RF components & modules for SatCom › Narda operates three accredited RF calibration labs. : Germany / US / Italy › Narda Test Solutions is part of L-3 Communications Group,
Slide 31: Who is Narda …
Who is Narda … › L-3 Communications › Established 1997 › 75 Business Units worldwide › Annual sales $12 billion (2013) › Some 50,000 employees › Narda Group › 10 Divisions … Narda Satellite Narda East Narda West … › › › 80 years in business 2,600 employees Core competence in › Microwave components ›