Page 88 - Concise Encyclopedia of Robotics

Digital Signal Processing (DSP)
“tidied up”so the pulse timing and amplitude adhere strictly to protocol.
Finally, the digital signal is changed back to analog form by means of
D/A conversion.
Digital signal processing can extend the workable range of a commu-
nications circuit, because it allows reception under worse conditions than
would be possible without it. Digital signal processing also improves the
quality of fair signals, so the receiving equipment or operator makes fewer
errors. The DSP process also ensures that the necessary communications
bandwidth is kept to a minimum.
Digital cleanup
In circuits that use only digital modes, A/D and D/A conversion are irrel-
evant, but DSP can nevertheless “tidy up” the signal. This improves the
accuracy of the system, and also makes it possible to copy data many
times (that is, to produce multigeneration copies).
The DSP circuit minimizes confusion between digital states, as shown
in the illustration.A hypothetical signal before processing is shown at the
top; the signal after processing is shown at the bottom. If the input ampli-
tude is above a certain level for an interval of time, the output is high
(logic 1). If the input amplitude is below the critical point for a time
interval, then the output is low (logic 0). A strong burst of noise might
Relative
amplitude
Signal before DSP

Time

Signal after DSP

Digital signal processing

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