A method in a Central Node (CN), a method in a Remote Node (RN), and a method in a wireless communication system for allocating reference signals to be used for uplink transmission are disclosed. According to one aspect reference signals are allocated with a method comprising the steps of: determining in a CN a number of reference signals N to be used for uplink transmission by a Remote Node RN; indicating to the RN the number of reference signals N to be used for uplink transmission by the RN; configuring an uplink transmission by the RN with at most the number of reference signals N; and performing by the RN the uplink transmission with at most the number of reference signals Non transmit antennas comprised in the RN. The present disclosure further discloses a CN and a RN relating to the methods.