Single Input Multiple Output (SIMO) is a multiple antenna system that operates with one antenna on the transmitting side and several on the receiving side. If such a multiple antenna system has two antennas on the receive side, it is referred to as Single Input Dual Output (SIDO).
The SIMO technique can also be used for mobile users whose reception location changes. In this case, the transmit beam is tracked to the reception location. This is done by transmitting test signals known to the receiver, which is used to determine the radiation angle. The SIMO technique prevents the emission of a transmit signal in the direction of another user, it increases the reception level by beamforming and reduces interference.