Abstract: An analog-to-digital converter can use a variable sampling rate. By using a variable sampling rate analog-to-digital converter and an anti-aliasing filter lower sampling rates, and accordingly, generally lower power consumption may be achieved. For example, a lower sampling rate can be used when it is determined that no undesirable signals are present and a higher sampling period can be used when an undesirable signal is present. Determining the presence of an undesired signal can be based on signal-to-noise ratio, over-sampling, bit error rate, using a detector, etc. An undesirable signal can be any signal that is close in frequency to a signal of interest or a signal farther away in frequency that has a relatively high amplitude. Sampling rate can be varied in a binary fashion, stepwise, continuously, etc.