Systems and methods can analyze a present channel estimation and a previous channel estimation and/or two or more prior channel estimations to improve communication performance, sense environmental conditions, and make location and velocity determinations. The methods can include: (a) sending, by a transmitter, a first sounding frame and a second sounding frame to a receiver; (b) receiving, by the transmitter, a first channel estimation response from a receiver responsive to the first sounding frame, and a second channel estimation response from the receiver responsive to the second sounding frame; and (c) detecting, by the transmitter, based at least on the first channel estimation response and the second channel estimation response, if a change in characteristics of a channel between the transmitter and the receiver occurred between the first sounding frame and the second sounding frame.