Communication device and method for collision detection

A communication device includes a radio transceiver and a collision detection device. The radio transceiver is configured to receive a wireless signal which includes an acknowledgment packet from a wireless communication channel. The acknowledgment packet includes acknowledgment information which corresponds to a plurality of transmitted packets. The collision detection device is coupled to the radio transceiver and configured to receive the acknowledgment packet, determine whether collision has occurred in the wireless communication channel according to the acknowledgment information corresponding to the acknowledgment information and accordingly generate a detection result. The collision detection device determines whether collision has occurred according to a distribution of the acknowledgment information having a predetermined acknowledgment status. When the collision detection device determines that the acknowledgment information having the predetermined acknowledgment status is concentrated in a section