Digital Signal Processing Reference
In-Depth Information
The best example of this trend is the
internet
, the worldwide network of innumerable
computer networks. Where do we still find analog technology here? The sound card is
usually the source of information and drain for real analog signals. It contains a minimum
of analog technology. Otherwise we only find analog technology at the transition to and
from the transmission medium Cu cable, optical wave guide, terrestrial relay radio and
satellite telephony.
Any kind of (analog) communication can be effected via the internet. Video webphoning,
i.e. world wide video telephony at local rates, is the latest step in this development.
In schools we are entering new territory with the digital
processing of real analog signals. At the present time there are no
ministerial guidelines or curricula which only as much as
mention the most important subject of modern information
technology, i.e. DSP or digital signal processing.
At present digital technology ends in schools with the A/D or D/A converter, that it the
point at which analog signals are converted into digital signals and vice versa. This should
be changed as quickly as possible.
DSP has made possible completely new, fantastic signal-processing systems. An excel-
lent example comes from the field of medical diagnostics in computer tomography, in
particular NMR-tomography (Nuclear Magnetic Resonance). The living human being is
recorded segment by segment by means of measuring technology and is presented picto-
rially. By linking the data from each “segment” using the computer it is possible given
sufficient computer capacity to navigate through the body of the living person, to repre-
sent bones and tissue separately and recognise and define certain tumours precisely.
It would be absolutely impossible to achieve this amazing feat using analog circuit
technology or analog computing technology. Another example is DASY
Lab
that we are
using. Highly complex signal processing systems can be programmed graphically and a
large number of details can be “visualised”, i.e. represented pictorially.
Digital processing of analog signals (DSP) makes new
applications of information technology (IT) possible, which
could not be realised using analog technology. Using a
computer, pure signal processing can be carried out virtually
at will with a degree of precision which borders on the limits
of nature as defined by physics.
DSP also leads to the standardisation of signalling processes. DAB and DVB (Digital
Audio Broadcasting and Digital Video Broadcasting) use signalling processes which are
also used in other modern technologies, for example, mobile telephony. Modern informa-
tion technology will in the final analysis become simpler and less complicated.
Not only will standard chips characterise hardware, standard
processes will characterise the software of signal processing
systems.
