There is disclosed a method of operating a network node, the network node operating according to a first radio access technology, RAT, the method including transmitting data in a transmission resource structure, the transmission resource structure including a first set of resource elements for data and a second set of resource elements for demodulation reference signals, DMRS, wherein the second set represents at least one pattern in frequency domain, wherein the transmission resource structure is scheduled based on a coexistence indication, the coexistence indication indicating the presence of cell-specific reference signals associated to a second RAT. The disclosure also pertains to related methods and devices.