With shortage of construction funds of operators, network sharing has become a universally used network construction manner. The network sharing is generally divided into a multioperator radio access network (MORAN for short) and a multioperator core network (MOCN for short). On the MOCN, multiple operators share a spectrum and a wireless access device. On the MORAN, multiple operators respectively have their own independent spectrums, and only share a wireless access device. For example, three operators respectively have their own independent spectrums, but share one radio frequency module and an antenna. In this way, for each operator, originally, a set of base station equipment needs to be set up for each operator; however, at present, the three operators use only one set of base station equipment. Therefore, 2/3 network construction costs may be saved, and additionally their own spectrum competitiveness can be ensured. The radio frequency module may be a remote radio unit (RRU for short), or a macro base station radio frequency unit (RFU for short).
A DD800M frequency band totally has a bandwidth of 30 M, which is successively divided into 3 carriers, C1, C2, and C3, according to the frequency band if 10 M is one carrier, where C1 is adjacent to C2 and C2 is adjacent to C3. The 3 operators each occupy a bandwidth of 10 M. To save network construction costs, the 3 operators use a three-party MORAN solution, which requires one radio frequency module to support 3 carriers, with one carrier for each operator. However, due to particularity of the DD800M frequency band, during implementation of the requirement, a problem that an intermodulation signal generated on a downlink interferes with an uplink signal occurs. Some of intermodulation signals generated in the 3 carriers and between the carriers on the downlink of the DD800M frequency band fall within an uplink frequency band interval, and severely interfere with an uplink signal of a base station, causing reduction of receiver sensitivity of the radio frequency module. Because transmit power of a downlink signal is very high, and the uplink signal is weak, if an intermodulation signal generated by the uplink signal falls within a downlink frequency band interval, interference to the downlink is small, and may be ignored. Besides the DD800M, another frequency band used in mobile communication also has a problem that an intermodulation signal generated on a downlink interferes with an uplink signal.
A solution of dual radio frequency modules can solve the foregoing problem of the intermodulation interference. Between two adjacent carriers C1+C2 or between two adjacent carriers C2+C3 of the DD800M frequency band, the intermodulation interference generated on the downlink does not fall within an uplink interval. In this way, 2 RRUs/RFUs and 2 dual-polarized antennas may be configured for each sector, two adjacent carriers C1+C2 or two adjacent carriers C2+C3 are configured on one radio frequency module, two adjacent carriers C2+C3 or two adjacent carriers C1+C2 are configured on the other radio frequency module, and the two radio frequency modules can support 3 carriers and implement a 3-party MORAN function after being combined. However, each sector needs to use 2 radio frequency modules, which increases a quantity of radio frequency modules, thereby increasing costs of devices and projects, and an objective of the MORAN is to share the radio frequency modules. Therefore, significance of the MORAN solution is reduced.