Image Number 15 for United States Patent #8041317.
A system includes a radio frequency transceiver. A baseband processor includes an automatic gain control module. The automatic gain control module has a gain that changes from and subsequently returns to a predetermined value each time the radio frequency transceiver receives a radio frequency signal. The baseband processor is configured to selectively generate an interrupt signal each time a radio frequency signal is received based on a magnitude of the change in the gain of the automatic gain control module and a length of time in which the gain returns to the predetermined value. A control module is configured to identify a radio frequency signal received by the radio frequency transceiver as a radar signal in response to the baseband processor having generated a plurality of interrupt signals at substantially equal time intervals.