Oversampling and decimation What filter to use?

1. Which filter is used in decimation and interpolation?
2. Why low-pass filter is used in decimation?
3. What is a decimation filter?
4. Why do we oversample and decimate?

Which filter is used in decimation and interpolation?

11.2 Polyphase Filter Structure and Implementation. Due to the nature of the decimation and interpolation processes, polyphase filter structures can be developed to efficiently implement the decimation and interpolation filters (using fewer number of multiplications and additions).

Why low-pass filter is used in decimation?

Decimation also is known as down-sampling. The lowpass filtering associated with decimation removes high-frequency content from the signal to accommodate the new sampling frequency. Decimation is useful in applications in which the Nyquist frequency of a signal is much higher than the highest frequency of the signal.

What is a decimation filter?

Loosely speaking, “decimation” is the process of reducing the sampling rate. In practice, this usually implies lowpass-filtering a signal, then throwing away some of its samples. “Downsampling” is a more specific term which refers to just the process of throwing away samples, without the lowpass filtering operation.

Why do we oversample and decimate?

Oversampling and Decimation is commonly used in ADC to improve the resolution. This technique requires large number of samples, these extra samples can be achieved by oversampling the input signal. Here oversampling refers to sampling the signal by a factor greater than the bare minimum Nyquist rate.