Which approach involves changing frequencies cyclically to mitigate jamming?

Which approach involves changing frequencies cyclically to mitigate jamming?

• A. Increase transmitted power
• B. Spread spectrum across wider bandwidth
• C. Freq hopping cycling
• D. Coherent jamming

Answer: (C)

The approach being tested is changing frequencies cyclically to avoid interference, known as frequency hopping cycling. By rapidly jumping the carrier among a set of frequencies in a predefined sequence, the transmitter and receiver stay synchronized, so a jammer cannot stay on the same frequency long enough to disrupt the link. This cycling forces the jammer to cover many frequencies, diluting its effect on any single channel and making it much harder to jam the communication consistently. Increasing power alone increases interference on all frequencies and can be ineffective against a strong jammer; it doesn’t prevent jamming by switching channels. Spreading spectrum across a wider bandwidth distributes the signal’s energy and provides processing gain to resist interference, but it doesn’t rely on cyclic frequency changes. Coherent jamming is a type of jamming technique, not an anti-jamming method, so it doesn’t describe a strategy for avoiding interference.

The approach being tested is changing frequencies cyclically to avoid interference, known as frequency hopping cycling. By rapidly jumping the carrier among a set of frequencies in a predefined sequence, the transmitter and receiver stay synchronized, so a jammer cannot stay on the same frequency long enough to disrupt the link. This cycling forces the jammer to cover many frequencies, diluting its effect on any single channel and making it much harder to jam the communication consistently.

Increasing power alone increases interference on all frequencies and can be ineffective against a strong jammer; it doesn’t prevent jamming by switching channels. Spreading spectrum across a wider bandwidth distributes the signal’s energy and provides processing gain to resist interference, but it doesn’t rely on cyclic frequency changes. Coherent jamming is a type of jamming technique, not an anti-jamming method, so it doesn’t describe a strategy for avoiding interference.