What is Digital Signal Processing?

Application of mathematical operations to digitally represented signals:
- Signals represented digitally as sequences of samples.
- microphones) and analog-to- digital converters (ADC).
- Digital signals converted back to physical signals via digital-to-analog converters (DAC).
- Digital Signal Processor (DSP): electronic system that processes digital signals.



The above figure represents a Real Time digital signal processing system. The measurand can be temperature, pressure or speech signal which is picked up by a sensor (may be a thermocouple, microphone, a load cell etc). The conditioner is required to filter, demodulate and amplify the signal. The analog processor is generally a low-pass filter used for anti-aliasing effect.

The ADC block converts the analog signals into digital form. The DSP block represents the signal processor. The DAC is for Digital to Analog Converter which converts the digital signals into analog form. The analog low-pass filter eliminates noise introduced by the interpolation in the DAC.



The performance of the signal processing system depends to the large extent on the ADC. The ADC is specified by the number of bits which defines the resolution. The conversion time decides the sampling time. The errors in the ADC are due to the finite number of bits and finite conversion time. Some times the noise may be introduced by the switching circuits.

Similarly the DAC is represented by the number of bits and the settling time at the output.

A DSP tasks requires:
- Repetitive numeric computations.
- Attention to numeric fidelity.
- High memory bandwidth, mostly via array accesses.
- Real-time processing.

And the DSP Design should minimize.
- Cost .
- Power.
- Memory use.
- Development time.

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