The present invention relates to a method in a network control node for transmission of control channel signals in a wireless communication system, the wireless communication system employing scheduling of physical resource blocks (PRBs) used for each new transmission of a control channel signal, wherein each control channel signal is related to one or more control channel elements (CCEs); the method comprising the steps of: removing user specific reference signals in associated physical resource blocks (PRBs) if the associated physical resource blocks (PRBs) comprises at least one control channel signal; inserting control channel signals in the associated physical resource blocks (PRBs); and transmitting the associated physical resource blocks (PRBs). Furthermore, the invention also relates to a computer program, a computer program product, and a network control node device thereof.