n his latest book, Dr. Poisel continues his in-depth description
of electronic warfare applied to modern communications technologies, specifically
direct-sequence spread-spectrum (DSSS) and ultrawideband communications. After
a thorough and fascinating introduction to signal propagation and the principles
of DSSS, jamming technologies, and signal detection, the book compares different
approaches to interfering with these digital communications. These methods include
old-fashioned broadband noise, partial-band noise, single- and multitone jamming,
pulsed jamming, and smart jamming. These more sophisticated technologies can be a
cat-and-mouse game as the senders adapt their encoding patterns to the new environment.
The signals are usually BPSK- or QPSK-modulated digital signals,
which are inherently more vulnerable than analog; but the processing gain afforded
by the bandwidth expansion makes them very difficult to intercept and expensive
Modern Communications Jamming Principles and Techniques
R. A. Poisel
Artech House, 2004, 479 pages
Ultrawideband signals are particularly resistant to interference because the
signal is typically below the noise floor of the receiver, making it difficult
to determine its presence. For fast frequency hopping (FFH) signals, in which the
frequency is changed more than once for each bit, following the signal becomes
even more difficult and the results of all the common forms of jamming are
dismal indeed. This is illustrated in chapter 9 with graphs showing that
narrowband noise and single-tone jamming, even at high jam/signal ratios, are
almost completely ineffective against Golay-encoded FFH bitstreams.
The author also describes his simulations, which clearly show the benefits of
using a forward detector (as opposed to a standoff configuration). The treatment
is at a high level, with numerous graphs and big honking equations, some of
which take up an entire page.
See also Introduction to Communication Electronic Warfare Systems.
Dec. 26, 2004