Frequency Hopping

It's a little known fact that a movie star and a musician co-invented and patented a major communications system during World War II. Hedy Lamarr and George Antheil devised frequency hopping as a method for communicating with radio-controlled torpedoes.

A radio signal whose carrier frequency changes at regular intervals is said to "hop" in frequency from one band to another. Frequency hopping spreads the signal spectrum over a wide band and helps to hide it from interceptors.

However, this form of spread-spectrum communications did not become popular until the 1980s, when researchers, such as those at CSL, brought it into the limelight.

Collision Detection
CSL used the detection of collisions - two transmitters using the same frequency at the same time - to significantly improve the performance of coded frequency-hopped communication systems.

Robust Detection and Estimation
Researchers developed robust communication systems that perform well, even when the models for noise and interference are not precisely known.