Beamforming transmission device and method

A beamforming transmission device, comprising:

• a baseband processing circuit, configured to provide at least one data stream and generate a control signal according to channel state information of at least two pieces of user equipment (UEs), wherein the data stream comprises data of the at least two pieces of user equipment;
• at least one radio frequency circuit, coupled to the baseband processing circuit, and configured to receive the data stream signal and generate at least one radio frequency signal;
• and
• an antenna array circuit, coupled to the baseband processing circuit and the at least one radio frequency circuit, and configured to receive the control signal and the at least one radio frequency signal and adjust gains and phases of the antenna array circuit according to the control signal such that the radio frequency signal is formed as a shared beamforming signal for transmitting to the at least two pieces of user equipment, wherein the shared beamforming signal comprises the data of the at least two pieces of user equipment;
• wherein the baseband processing circuit is further configured to calculate gains corresponding to the at least two pieces of user equipment according to a cost function of the channel state information of the at least two pieces of user equipment, and next calculate a precode according to the gains corresponding to the at least two pieces of user equipment and the channel state information of the at least two pieces of user equipment, and then generate the control signal according to the precode.