Types of interpolation used for reconstruction in DSP?

1. What is interpolation in DSP?
2. Why interpolation is used in DSP?
3. What type of interpolation does a square pulse use in order to reconstruct an analogue signal?
4. What type of filter is used for reconstruction Why?

What is interpolation in DSP?

In the domain of digital signal processing, the term interpolation refers to the process of converting a sampled digital signal (such as a sampled audio signal) to that of a higher sampling rate (Upsampling) using various digital filtering techniques (for example, convolution with a frequency-limited impulse signal).

Why interpolation is used in DSP?

Interpolation is the process of increasing the sampling frequency of a signal to a higher sampling frequency that differs from the original frequency by an integer value. Interpolation also is known as up-sampling.

What type of interpolation does a square pulse use in order to reconstruct an analogue signal?

The ideal is the Whittaker-Shannon interpolation formula, or sinc interpolation. This is equivalent to convolution of the signal data with a sinc function, the impulse response of an ideal lowpass filter, at half the sample rate.

What type of filter is used for reconstruction Why?

The reconstruction filter, at the output of the DAC, is usually a high order Bessel or elliptic filter used to low pass filter the analog output from the DAC.