The most immediate reason to decimate is simply to reduce the sampling rate at the output of one system so a system operating at a lower sampling rate can input the signal. ... For example, if you double the sample rate, an equivalent filter will require four times as many operations to implement.

How does decimate work?

Decimation is a term that historically means the removal of every tenth one. But in signal processing, decimation by a factor of 10 actually means keeping only every tenth sample. ... For example, if compact disc audio at 44,100 samples/second is decimated by a factor of 5/4, the resulting sample rate is 35,280.

Why do we downsample a signal?

Downsampling. The idea of downsampling is remove samples from the signal, whilst maintaining its length with respect to time. For example, a time signal of 10 seconds length, with a sample rate of 1024Hz or samples per second will have 10 x 1024 or 10240 samples.