a system for the coexistence between a plurality of wireless communication modules sharing a single antenna is provided , including an antenna , first and second transceiving paths , and first and second wireless communications modules . the first transceiving path is coupled to the antenna . the second transceiving path is coupled to the first transceiving path . the first wireless communications module is coupled to the first transceiving path and transmits or receives a plurality of first wireless signals . the second wireless communications module is coupled to the second transceiving path and transmits or receives a plurality of second wireless signals , wherein signal strengths of the second wireless signals passing through the second transceiving path are attenuated by a certain level , and the attenuated second wireless signals are added to the first wireless signals when passing through the first transceiving path .