A data communication scheduling system (300) of a radio base station (100) serving multiple cells (10-30) comprises multiple radio equipment, REs, (101-103) and antenna interfaces (115, 125, 135) connectable to antennas (110, 120, 130). In order to reduce the power consumption, only a subset of the RE (101) is active, while the other REs (102, 103) are turned off. A transmitter controller (155) is arranged for controlling the active RE (101) to be shared among multiple cells (10-30) during a radio frame (40) so that each cell (10-30) is guaranteed at least one sub frame (50-58) for downlink transmission. A receiver antenna system multiplexer(140) selectively interconnects the active RE (101) with the antenna interfaces (115, 125, 135) according to the operation of a receiver controller (145). Consequently, the RE (101) becomes connected to different antenna interfaces (115, 125, 135) during different sub frames (50-58) to thereby allow each cell (10-30) at least one assigned uplink sub frame (53-55) in the radio frame (40) at a predefined sub frame distance after the at least one downlink sub frame (50-52) assigned to the same cell (10-30).