Dr. Fred J. Taylor, Professor
Signal processing refers to the art and science of creating, modifying, manipulating, extracting, and
displaying information and attributes from signals. Since the dawn of time, man has been the
quintessential signal processor. Signal processing was performed by the most powerful signal
processing engine ever developed, the
human brain, which commits about
information processing (comparable to an Intel mobile Pentium III processor). As humans evolved,
other elements were added to man’s signal processing environment and repertoire, such as
information coding in terms of intelligent speech
and the written word.
In time, communication links
expanded from local, to global, to galactic.
It was the introduction of electronics, however,
enabled the modern information revolution.
The earliest, analog electronics, gave rise to such
innovations as the plain old telephone system (POTS), radio, television, radar/sonar and a host of
other inventions that have revolutionized man’s life. With the introduction of digital technologies over
a half century ago, man has witness an explosion of innovations that have
of many of the analog solutions to system having a high digital content. In other instances, digital
solutions that previously never existed. Included in this list include digital
entertainment systems, digital controllers, digital cameras, digital mobile telephony, and so forth. In
some cases, digital technology has been a
, giving rise to products that where
impossible to envision prior to the technologies existence. An example of this is the now ubiquitous
personal digital computer.
Origins of Modern Signal Processing
The foundations of modern signal processing were laid in the middle of the 20
Century. To some
the master mason was Claude Shannon, and others, Harry Nyquist. Both can be credited with
that described how a continuous signal could be represented by a
set of periodic samples. The representation was found to be so perfect that the original signal could
be reconstructed from a sparse set of discretely distributed samples. The work of Shannon and
Nyquist provided both the key and the motivation to convert signals from their natural continuous-
time form into a domain characterized by sample values which, today, and digital words. Since then
analog and digital technologies have increasingly been fused together to define a technical area
called digital signal processing (DSP).
During the 1950s, and into the 1960s, digital computers began to make their initial appearance on
the technology scene. These early computing machines were considered to be far too costly to be
used in the mundane role of signal analysis or as a laboratory support tool by lowly engineers.
1965, Cooley and Tukey
introduced an algorithm that is now known as the