Howtosignalprocessing
- How do you downsample a signal?
- What is the difference between decimation and downsampling?
- Why decimate a signal?
- Why do we 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.
What is the difference between decimation and downsampling?
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 decimate a signal?
Decimation is useful in applications in which the Nyquist frequency of a signal is much higher than the highest frequency of the signal. Decimation filters help you remove the excess bandwidth and reduce the sampling frequency of the signal.
Why do we 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.
