A method forms polar diagrams in a connection between a subscriber and a base station with an antenna arrangement in a radio communications system using multiple access methods. Antenna signals are associated with polar diagrams of the antenna arrangement by a common beam forming network. The common beam forming network is used to form weighted sum signals, which are passed as input signals to a user-specific beam forming unit. A selector which is arranged there takes from the input signals a user-specific subset Kc of signals, to which an eigen polar diagram forming algorithm is applied.