Wireless transmission system and communications method

In the present invention, a wireless transmission system includes a plurality of mobile stations in a cell area, and a base station. The base station divides each of an uplink frame and a downlink frame into a plurality of blocks, assigns a specific one of the plurality of blocks to each of the plurality of the mobile stations, assigns a specific frequency channel to the mobile station, and notifies the specific block and the specific frequency channel to the mobile station. The length of each of the plurality of blocks is optional, and a sum of the lengths of the plurality of blocks is equal to the length of the frame.