Patent ID: 8675688

Claim:
An apparatus for receiving a wake-up signal, the apparatus comprising: an amplifier unit including at least two amplifying portions; a radio frequency (RF) receiving unit receiving a wireless signal through an antenna; a start of frame delimiter (SFD) detecting unit detecting an SFD to indicate that the received wireless signal is a wake-up signal that is used to wake-up a node in a sleep mode, by operating the RF receiving unit during an SFD detecting time, wherein the SFD detecting time is shorter than a predetermined SFD detecting time period; and a wake-up signal detecting unit detecting the wake-up signal by continuously operating the RF receiving unit when the SFD is detected, wherein less than all of the at least two amplifying portions are operated prior to the SFD being detected and all of the at least two amplifying portions are operated after the SFD is detected, and wherein the SFD detecting unit samples values of the wireless signal that is received by the RF receiving unit a number of times that is larger than a ratio that is obtained by dividing the predetermined SFD detecting time period by the SFD detecting time and extracts a value that is obtained by performing an OR operation on the sampled values.