Introduction to Digital Signal Processing - Digital Signal Processing: Fundamentals and Applications - page 13

However, the list in the table by no means covers all DSP applications. Engineers and scientists are
exploring many new potential applications. DSP techniques will continue to have a profound impact
and improve our lives.
1.5 SUMMARY
1. An analog signal is continuous in both time and amplitude. Analog signals in the real world include
current, voltage, temperature, pressure, light intensity, and so on. The digital signal contains the
digital values converted from the analog signal at the specified time instants.
2. Analog-to-digital signal conversion requires an ADC unit (hardware) and a lowpass filter attached
ahead of the ADC unit to block the high-frequency components that ADC cannot handle.
3. The digital signal can be manipulated using arithmetic. The manipulations may include digital
filtering, calculation of signal frequency content, and so on.
4. The digital signal can be converted back to an analog signal by sending the digital values to DAC to
produce the corresponding voltage levels and applying a smooth filter (reconstruction filter) to the
DAC voltage steps.
5. Digital signal processing finds many applications in the areas of digital speech and audio, digital
and cellular telephones, automobile controls, vibration signal analysis, communications,
biomedical imaging, image/video processing, and multimedia.