How to downsample a fourier transformed signal?

1. How do you downsample a signal?
2. How do you overcome the limitation of a Fourier transform?
3. Which signals can be down sampled?
4. Why do you downsample a signal?

How do you downsample a signal?

y = downsample( x , n ) decreases the sample rate of x by keeping the first sample and then every n th sample after the first. If x is a matrix, the function treats each column as a separate sequence. y = downsample( x , n , phase ) specifies the number of samples by which to offset the downsampled sequence.

How do you overcome the limitation of a Fourier transform?

The solution to this is time-frequency analysis, which is a field that deals with signal processing in both time and frequency domain.

Which signals can be down sampled?

5 Which signals can be downsampled? A signal can be downsampled (without doing any filtering) whenever it is “oversampled”, that is, when a sampling rate was used that was greater than the Nyquist criteria required. Specifically, the signal's highest frequency must be less than half the post-decimation sampling rate.

Why do you downsample a signal?

(1) To make a digital audio signal smaller by lowering its sampling rate or sample size (bits per sample). Downsampling is done to decrease the bit rate when transmitting over a limited bandwidth or to convert to a more limited audio format.