A wireless communications system includes a base station and multiple mobile stations performing wireless communication with the base station in a DS-CDMA scheme. Each of the mobile stations has a transmission unit configured to transmit a timing difference detection packet to the base station, prior to transmitting packet data. The base station has a transmission timing control unit configured to detect a difference in signal receive timing from the mobile stations based on the timing difference detection packet, produce transmission timing control information for each of the mobile stations based on the detection result, and supply the transmission timing control information to each of the mobile stations to cause the mobile stations to adjust the transmission timing of the packet data.