The invention relates to a data processing method, a host unit, a base station system and a storage medium. The host unit acquires measurement data reported by an expansion unit; wherein the measurement data is obtained by the expansion unit based on an uplink signal sent by same user equipment and is used for indicating the signal transmission quality between each far-end unit group connected with the expansion unit and the user equipment. Then, a judgment is made whether the signal of the user equipment is interfered or not according to the measurement data; and if the signal of the user equipment is interfered, a judgment is made that at least two target far-end unit groups from the plurality of far-end unit groups to receive an uplink signal sent by the user equipment. The uplink signal quality of the user equipment can be improved while the forward bandwidth requirements of the host unit and the expansion unit are reduced.