Anti-Jam Techniques/ AJ

Definition

Anti-jam techniques include frequency hopping, direct-sequence spread spectrum, beam-nulling antennas, low probability of intercept/detection waveforms, and adaptive coding and modulation. In modern tactical meshes they are layered with cognitive-radio policy and routing-protocol resilience so that link, network, and application layers each contribute to surviving an EW attack.

Reference attributes

Waveform-layer

FHSS, DSSS, LPI/LPD

Antenna-layer

Adaptive nulling, CRPA

Network-layer

Re-routing, store-and-forward

Related terms

• Frequency-Hopping Spread Spectrum (FHSS)
  Spread-spectrum technique that rapidly changes carrier frequency over a wide band.
• Direct-Sequence Spread Spectrum (DSSS)
  Spread-spectrum technique that multiplies the data signal by a high-rate pseudo-noise code.
• Low Probability of Intercept (LPI)
  Waveform property that minimizes the chance of detection by adversary signals intelligence.
• Controlled Reception Pattern Antenna (CRPA)
  Adaptive antenna array that nulls jammers by steering its reception pattern.