CSI RS AND DMRS CO LOCATION INDICATION

摘要

Embodiments herein relate to a method in a user equipment (10) for performing channel estimation of one or more long term channel properties at the user equipment (10) wherein the user equipment (10) is served by a radio network node (12). The user equipment (10) assumes that a default Channel State Information Reference Signal CSI RS resource is co located with a Demodulation Reference signal DMRS port when co location is not explicitly signalled from the radio network node (12) wherein the default CSI RS resource is configured by reading a predetermined entry in a configurable list of candidate co location CSI RS resources for a dynamic indication of co location options in a Downlink Control Information DCI format. When assumed to be co located the user equipment (10) estimates one or more long term channel properties of the DMRS port and the default CSI RS resource based on the assumption that the default CSI RS resource is co located with the DMRS port.