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The rationale of replacing signal analog processing by digital, worth doing whenever
it is feasible, is well known. The benefits that can be obtained are usually
significant. Digital signal processing (DSP) technology is widely used in the
application range characterized by relatively low frequencies and other acceptable
application conditions. However, ‘going digital’ becomes more difficult and
even problematic as application demands grow. Some nontraditional methods,
techniques and algorithms are suggested in this book for widening the digital
domain over the application area where analog signal processing techniques still
prevail.
Much attention is paid to resolving the problems caused by overlapping of
periodically sampled signal frequencies. This effect, known as aliasing, restricts
application of the conventional digital signal processing methods and techniques
to the frequency range where the achievable sampling rate could at least twice
exceed the higher frequency present in the spectrum of the signal to be digitized
and processed digitally. Attempts to eliminate the harmful impact of aliasing
have led to the development of digital technology for signal processing, specifically
the technology called digital alias-free signal processing, or DASP. This
strengthens the competitiveness of digital techniques considerably. Successful
use of special digitizing techniques for the elimination of aliasing has been an
object lesson showing the significance of digitizing in the whole process of signal
digital processing.
Focusing on digitizing and matching of signal processing to the specifics of
signal sampling and quantizing operations has led to other significant improvements
in digital signal processing methods and techniques. In fact, many signal
processing problems can be resolved in this way. These considerations and the
experience gained in this area are described in the book. |