Abstract: An antenna structure includes a ground element, a feeding radiation element, a first radiation element, a second radiation element, a shorting radiation element, a third radiation element, and a fourth radiation element. The feeding radiation element has a feeding point. The first radiation element is coupled to the feeding radiation element. The second radiation element is coupled to the feeding radiation element. The second radiation element and the first radiation element substantially extend in opposite directions. The feeding radiation element is further coupled through the shorting radiation element to the ground element. The third radiation element is coupled to the ground element. The third radiation element is adjacent to the first radiation element. The fourth radiation element is coupled to the ground element. The fourth radiation element is adjacent to the second radiation element.

Abstract: A receiver device is configured to receive a packet. The receiver device includes a physical layer circuit. The physical layer circuit is configured to demodulate the packet to acquire at least one indicator associated with the packet, and determine whether the packet is an abnormal packet or not according to the at least one indicator. If the packet is the abnormal packet, the physical layer circuit drops the packet.

Abstract: A receiver device is configured to receive a packet. The receiver device includes a physical layer circuit. The physical layer circuit is configured to demodulate the packet to acquire at least one indicator associated with the packet, and determine whether the packet is an abnormal packet or not according to the at least one indicator. If the packet is the abnormal packet, the physical layer circuit drops the packet.

Abstract: A wheelchair including a seat body and at least one wheel module disposed at a bottom of the seat body is provided. The wheel module includes a motor, at least one wheel, and a transmission unit coupled between the motor and the wheel. The transmission unit has at least one one-way bearing. The motor outputs a first rotating moment and a second rotating moment with opposite directions to the transmission unit. The one-way bearing transmits one of the first rotating moment and the second rotating moment to the wheel to drive the wheel to roll, such that the seat body is in linear motion, or so the wheel module rotates relative to the seat body in the directions of the first or the second rotating moments. The shafts of the first and the second rotating moments are perpendicular to the rotating shaft of the wheel.

Abstract: A wheelchair including a seat body and at least one wheel module disposed at a bottom of the seat body is provided. The wheel module includes a motor, at least one wheel, and a transmission unit coupled between the motor and the wheel. The transmission unit has at least one one-way bearing. The motor outputs a first rotating moment and a second rotating moment with opposite directions to the transmission unit. The one-way bearing transmits one of the first rotating moment and the second rotating moment to the wheel to drive the wheel to roll, such that the seat body is in linear motion, or so the wheel module rotates relative to the seat body in the directions of the first or the second rotating moments. The shafts of the first and the second rotating moments are perpendicular to the rotating shaft of the wheel.