The present invention relates to a node (1) in a wireless communication system, the node (1) comprising at least one antenna (2) which is arranged to cover a first sector (3) in a first direction (4) and comprises a number (A) of antenna ports (5, 6, 7, 8), which number (A) is at least four. The antenna ports (5, 6, 7, 8) are connected to a transformation matrix (9) which is arranged for transforming the antenna ports (5, 6, 7, 8) to at least a first set (S1) of virtual antenna ports (10, 11) and a second set (S2) of virtual antenna ports (12, 13), each set (S1, S2) comprising a number (B) of virtual antenna ports (10, 11; 12, 13). The present invention also relates to a corresponding method.