ENERGY DETECTION METHOD WITH LOW POWER CONSUMPTION AND COMMUNICATION DEVICE THEREOF

An energy detection method includes the following steps: controlling a communication device (STA) to enter a sleep mode during a first time interval (T1); intermittently turning on and turning off a part of receiving functions of the communication device (STA) during a second time interval (T2), in which the second time interval (T2) is after the first time interval (T1), and when the part of receiving functions of the communication device (STA) are turned on, the communication device (STA) is controlled to receive a signal; and determining if a beacon signal is present according to energy of the signal received by the communication device (STA). First average power consumption of the communication device (STA) during the second time interval (T2) is smaller than second average power consumption of the communication device (STA), in which the second average power consumption corresponds to enabling all receiving functions of the communication device (STA).