Digital Signal Processing Reference
In-Depth Information
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Time
Sh - e S - ell - s S - ea Sh - ell - s
FIGURE 1.1
Time waveform of “She sells sea shells.”
Audio input
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Stage
Modulation
Channel
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Demodulation
Audio output
FIGURE 1.2
Block diagram of digital communications system.
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Analyzing the analog signal to obtain useful information.
This application
is useful for biomedical signals, such as EKG (heart) and EEG (brain).
In such a case, the analog signal is sampled and then analyzed using
a FFT. The FFT spectrum of the EKG, for example, can reveal several
useful parameters about the patient, such as high potassium levels
(hyperkalemia) or low potassium levels (hypokalemia).
