US Patent 9933517 Time-alignment of motion detection signals using buffers

In a general aspect, a filter time aligns time varying RF-motion data. In some aspects, a method includes loading a first set of input signals (SISs) into an interference buffer over a first time period. The first SISs is based on a first set of wireless signals received by a wireless communication device (WCD) after being transmitted through a space. The method includes using the first SISs to determine an interference level. The method includes: in response to determining the interference level is below a threshold, executing a motion detection process in a second, subsequent time period over which a second SISs is loaded into the interference buffer. The motion detection process, using a subset of the first SISs, detects motion of an object in the space. The second SISs are based on a second set of wireless signals received by the WCD after being transmitted through the space.