A radio access node comprises four logical antenna ports respectively mapped to four physical antennas. Responsive to a loss of data transmission from one of the four physical antennas, the radio access node transmits reference signals representing the four logical antenna ports on the remaining three physical antennas. Each reference signal represents a respective antenna port of the four logical antenna ports. The radio access node also scales transmission power of a physical antenna transmitting more than one of the reference signals based on the number of the reference signals the physical antenna transmits.