A system for the coexistence between a plurality of wireless communication modules sharing a single antenna includes an antenna, first and second transceiving paths, and first and second wireless communications modules. The first wireless communications module is coupled to a first transceiving path and transmits or receives first wireless signals via the first transceiving path. The second wireless communications module is coupled to the second transceiving path and transmits and receives second wireless signals via the first and the second transceiving paths, 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, wherein one of the first and the second communications module is a LTE module and the other one is a WLAN module.