Howtosignalprocessing
- How did the lower sample rate change the DFT results?
- How does sample rate affect FFT?
- What happens when you lower the sample rate?
- How can sampling rate be reduced?
How did the lower sample rate change the DFT results?
If you down-sample your data to a lower sample rate (after proper bandlimiting and/or low-pass filtering, etc.), then the duration or time covered by the same number of samples at the new lower sample rate will increase, thus allowing more frequency resolution in terms of FFT bin spacing (for an FFT of the same vector ...
How does sample rate affect FFT?
The amplitude of the DFT (FFT) is proportional to the number of samples. Therefore, if you sample for twice as long at the same sampling frequency, or if you sample for the same duraiton but twice as fast, you will have twice as many data points, and the DFT amplitude will be twice as large. See examples below.
What happens when you lower the sample rate?
If lower sampling rates are used, the original signal's information may not be completely recoverable from the sampled signal or it may result in an audible artifact known as “aliasing.” (We'll talk more about aliasing later in this article.)
How can sampling rate be reduced?
Decimation is a process in which sampling rate is reduced. It is also called down sampling. Consider a discrete time signal x (n). The sampling rate of x (n) can be reduced by a factor 'D' by taking every Dth sample of signal.
