Course Length: 2 Days

Prerequisites: NONE

Course Objectives:

This course is for anyone who is involved with interference hunting in radio services. It will provide theoretical and practical fundamentals needed to effectively identify and locate radio frequency interference issues in any band or network. It begins with an overview of basic RF principles, signal types, propagation and spectrum allocation.

Practical applications include interference hunting tools, the use of monitoring receivers, spectrum analyzers and drive test tools. Methods of radiolocation (direction finding) and signal analysis will be demonstrated using live signal sources and hands-on exercises

General RF principles

  • Frequency / wavelength (relationship between)
  • Power / attenuation (how to measure, etc.)
  • Measurement units (dBm, dBμV, conversions,
    etc.)
  • Modulation vs. unmodulated signals
  • Noise (including noise floor)

Signal characteristics

  • Bandwidth
  • Analog modulation types (CW, AM, FM, etc.)
  • Digital modulation types (FSK, QPSK, QAM, etc.)

Propagation

  • Propagation characteristics by frequency range
  • Factors affecting propagation
  • External signal sources
  • Reflections / multipath

Spectrum overview

  • General overview of spectral allocations
  • Technology specific overviews (US cellular bands, military, etc.)
  • Setting References — Base lining
  • Spectrum clearing/re-farming
  • Researching spectral allocations / licensing

Antennas

  • Mechanics of coaxial connectors
  • Preparing cables for connectors
  • Installing connectors

Basic principles of direction finding

  • What is direction finding?
  • Uses of direction finding
  • Overview / comparison of direction-finding methodologies
  • Mapping / triangulation

Basic spectral analysis

  • Understanding and interpreting spectrum displays
  • Understanding and interpreting waterfall diagrams (spectrograms)
  • Other spectral analysis modes (persistence display, e.g.)
  • Numerical measurements (use of markers/lines)

Radio Interference types

  • Modulated vs. unmodulated sources
  • Uncorrelated interference / noise floor issues
  • Patterns in interference (time of day, reactive)
  • Interference Types
    • Intermodulation
    • Harmonics
    • Spurious Emissions

Recognizing interference issues

  • Typical signs of interference
  • Interpreting spectral issues
  • Diagnosing interference using instruments

Analyzing specific interference issues

  • Harmonics / intermodulation
  • Narrowband vs. wideband interference
  • Use of demodulation / signal analysis
  • Device-specific interference (e.g. jammers, BDAs, etc.)
  • Long-term monitoring / recording

Location of interfering signals

  • Common transmitter and antenna types
  • Interference-prone locations
  • Use of drive-test / vehicle tools
  • Use of handheld / portable tools
  • Antennas and direction finding systems

Resolving interference issues

  • Determining type/location of interfeering device
  • Communication with owners of interfering
  • Understanding legal/regulatory issues and remedies

About – Practical exercises

  • Diagnosing and locating indoor interference
  • Diagnosing and locating outdoor interference
  • Handheld, on-foot interference hunting (“last 100 meters”)
  • Source analysis (“last inch”)
  • Interference hunting challenges