A system includes a base station (BS) and a user equipment (UE). The BS is capable of communicating with the UE via a serving cell and a coordinated cell. The BS includes a frequency exchange module coupled with a first baseband processing unit and a second baseband processing unit. The first baseband processing unit is designated for supporting baseband processing related to the coordinated cell, and the second baseband processing unit is designated for supporting baseband processing related to the serving cell. The frequency exchange module is configured to forward a first frequency domain signal to the second baseband processing unit according to a first predetermined coordination configuration relating to the serving cell of the UE and the coordinated cell of the UE. The second baseband processing unit is configured to perform a joint processing of the first frequency domain signal and a second frequency domain signal.