The invention discloses a
data transmission method, a
base station, a terminal and a mobile communication
system. The
data transmission method comprises the following steps: configuring an uplink spectrum in a paired spectrum to a full duplex spectrum by the
base station; and configuring corresponding resources of the terminal in a sub-frame to implement
downlink transmission in the full duplex spectrum when the
base station determines that the terminal does not need to transmit data or feed back information in the sub-frame of an uplink radio frame according to a timing relationship of HARQ, and transmitting
resource scheduling information of sub-frame uplink and
downlink transmission on the full duplex spectrum or downlink spectrum. According to the
data transmission method, the base
station, the terminal and the mobile communication
system disclosed by the invention, the
downlink transmission can be distributed in the uplink spectrum, and thus frequency resources of the network can be used more flexibly, the efficiency of the frequency can be increased, the frequency resources of operators can be used more effectively, simplicity and small access
delay can be achieved, good compatibility can be brought to different versions of the terminals, and the
throughput of the whole
system and terminal experiences can be improved.