The present invention relates to a network node and a method performed by the network node for controlling communication between a radio base station, RBS, and user equipments, UEs. The RBS has multiple antennas and uses beam forming when communicating with the UEs. The method comprises obtaining (702) information on an expected first propagation path direction interval between the RBS and UEs served by other neighboring RBSs, and obtaining (704) information on an expected second propagation path direction interval between the RBS and served UEs; defining (706) a first communication power limit for each of a plurality of beams according to the obtained information, the first limit being defined to suppress communication power in the first propagation path direction interval, when the plurality of beams are transmitted; and determining (708) antenna weights for each of the plurality of beams based on the defined first communication power limit.