CPRI, namely the common public radio interface, is a common standard of the key internal interface between the REC and the RE of the wireless base station. This standard was established by Huawei, Ericsson, NEC, Siemens, and Nortel in June 2003. It aims at standardizing the baseband and RF interface. The major feature of the CPRI is that baseband signals are separated from RF signals to reduce the cost of the engineering construction, equipment room, and equipment.