Noise reduction using multiple recordings of the same signal

1. Which technique is used to remove noise from data?
2. Which signal is used in communication process to minimize the effect of noise?

Which technique is used to remove noise from data?

Under-sampling: Unlike oversampling, this technique balances the imbalance dataset by reducing the size of the class which is dominant among the two classes.

Which signal is used in communication process to minimize the effect of noise?

A more effective way to avoid noise, however, is to covert the analog signal to a digital signal instead of amplifying it. As shown in Figure 4, digital signals, with their set of discrete bits, are far more immune to noise than analog.