B. P. Lathi, Zhi Ding - Modern Digital and Analog Communication Systems-Oxford University Press (2009)

11.3 Applications of FHSS 623
To combat jamming, SINCGARS radios can implement frequency hopping at the rather
slow rate of 100 Hz. Because the hopping rate is quite slow, SINCGARS is no longer effective
against modern jamming devices. For this reason, SINCGARS is being replaced by the newer
and more versatile JTRS Uoint tactical radio system).
From Hollywood to CDMA
Like many good ideas, the concept of frequency h opping also had multiple claims of inventors.
One such patent that gained little attention was awarded to Willem Broertjes of Amsterdam,
Netherlands, in August 1932 (U.S. Patent no. 1,869,659). 5 However, the most intriguing patent
on frequency hopping came from one of Hollywood's well-known actresses during World
War II, Hedy Lamarr. In 1 942 she and her coinventor George Antheil (an eccentric composer)
were awarded U.S. patent no. 2,292,387 for their "Secret Communications System." The patent
was designed to make radio-guided torpedoes harder to detect or to jam. Largely because of the
Hollywood connection, Hedy Lamarr became a legendary figure in the wireless communication
community, often credited as the inventor of CDMA, whereas other less glamorous figures
such as Willem Broertjes have been largely forgotten.
Hedy Lamarr was a major movie star of her time. 6 Born Hedwig Eva Maria Kiester in
Vienna, Austria, she first gained fame in the 1933 Austrian film Ecstasy for some shots that
were highly unconventional in those days. In 1937, escaping the Nazis and her first husband (a
Nazi arms dealer), she went to London, where she met Louis Burt Mayer, cofounder and boss
of the MGM studio. Mayer helped the Austrian actress's Hollywood career by giving her a
movie contract and a new name-Hedy Lamarr. Lamarr starred with famous colleagues such
as Clark Gable, Spencer Tracy, and Judy Garland, appearing in more than a dozen films during
her film career.
Clearly gifted scientifically, Hedy Lamarr worked with George Antheil, a classical composer,
to help the war effort. They originated an idea of a sophisticated antijamming device for
use in radio-controlled torpedoes. In August 1942, under her married name at the time, Hedy
Kiesler Markey, Hedy Lamarr was awarded U.S. Patent no. 2,292,387 (Fig. 11.7), together with
George Antheil. They donated the patent as their contribution to the war effort. Drawing inspiration
from the composer's piano, their invention of frequency hopping uses 88 frequencies,
one for each note on a piano keyboard.
However, the invention would not be implemented during World War II. It was simply
too difficult to pack vacuum tube electronics into a torpedo. The idea of frequency hopping,
nevertheless, became reality 20 years later during the 1962 Cuban missile crisis, when the
system was installed on ships sent to block communications to and from Cuba. Ironically,
by then, the Lamarr-Antheil patent had expired. The idea of frequency hopping, or more
broadly, the idea of spread spectrum, has since been extensively used in military and civilian
communications, including cellular phones, wireless LAN, Bluetooth, and numerous other
wireless communications systems.
Only in recent years has Hedy Lamarr started receiving a new kind of recognition as a
celebrity inventor. In 1997 Hedy Lamarr and George Antheil received the Electronic Frontier
Foundation (EFF) Pioneer Award. Furthermore, in August 1997, Lamarr was honored with the
prized BULBIE Gnass Spirit of Achievement Bronze Award (the "Oscar" of inventing). If she
had won an Academy Award for her film works in film, she would have been the only person
to receive two entirely different "Oscar" awards! Still, inventors around the world are truly
delighted to welcome a famous movie celebrity into their ranks.
Inventor Hedy Kiesler Markey died in 2000 at the age of 86.