An apparatus for wireless communication includes a classification unit and an allocation unit. The classification unit classifies communication devices in a cell where the apparatus is located, the communication devices are classified into a plurality of communication device groups including a first communication device group and a second communication device group. The allocation unit allocates pilot frequency sequences in a first pilot frequency group to the first communication device group, and allocates pilot frequency sequences in a second pilot frequency group to the second communication device group. When the number of the pilot frequency sequences is insufficient, a multiplexing configuration is executed, such as communication devices in the second communication device group multiplex at least one pilot frequency sequence in the second pilot frequency group.