| 摘要 |
A low-power wireless communication apparatus comprises a low-noise amplifier 203 for amplifying a radiofrequency signal, a wake up signal detector 205 for receiving the amplified radiofrequency signal and a controller 210 for providing a predetermined ON/OFF control signal to the low noise amplifier 203, wherein in a sleep mode corresponding to a receive waiting state, the predetermined control signal controls the low noise amplifier 203 (and preferably the wake up signal detector 205) to operate at a predetermined on-off duty ratio and where, when a wake up signal is detected in the sleep mode, the apparatus is switched to a receive mode where the low-noise amplifier 203 is maintained in an on state. Switches 202, 204 may be used to connect the antenna 201 and low noise amplifier 203 to the wake up signal detector 205 in the sleep mode and to the receiver 206 in the receive mode. The detection of a wake up signal in the sleep mode preferably comprises amplifying, rectifying and integrating the signal to see if it exceeds a predetermined threshold (Figure 3). The detected signal may then be deemed valid if a valid data packet is received in the receive mode, enabling the apparatus to wake up to perform transmit and receive operations. The apparatus returns to the sleep mode, directly or after a predetermined off mode, when transmit and receive operations are complete or when the detected wake up signal is deemed invalid (Figures 4 and 7b). The on-off duty ratio may be set depending on the communication environment. Power is saved by controlling the on/off operation of different components in the sleep, receive, transmit and off modes (Figure 5). |
