A method in a node (110, 115) comprises generating (704) a frame structure comprising at least a first subframe (305, 405, 505), the first subframe comprising a first symbol (310A, 510A) and a second symbol (310B, 510B), each of the first and second symbols comprising a plurality of resource elements. The method comprises reserving (708) one or more of the plurality of resource elements in the first symbol for reference signals (335A-G, 435A-G, 535A-G), modulating (712) one or more of the reserved resource elements in the first symbol with reference symbols (335B-D, 435B-D, 535B-D), the modulated one or more of the reserved resource elements in the first symbol comprising a subset of the one or more reserved resource elements that overlap in frequency domain the data transmission carried in the second symbol, and transmitting (716) the at least one subframe to another node.