JOINT FIRST REFERENCE SIGNAL AND SECOND REFERENCE SIGNAL BASED CHANNEL STATE INFORMATION FEEDBACK

摘要

The exemplary embodiments of this invention improve channel state information (CSI) feedback quality from a user equipment (UE) by using two different reference signals, such as cell-specific reference signals(CRS) and channel state information reference signals (CSI-RS), for CSI measurement and associated reporting. In an embodiment a method includes determining if at least one criterion is satisfied; if the at least one criterion is satisfied combining a first channel estimate based on a received CRS with a second channel estimate based on a received CSI-RS; and transmitting a CSI report to a network access node, where the channel state information report being based on the combined first channel estimate and second channel estimate. The determining of whether the at least one criterion is satisfied includes determining if the received cell-specific reference signal and the received channel state information reference signal were transmitted from the same antenna port of the network access node. In one embodiment this determination is made by the UE, while in another embodiment the UE receives signaling the network access node that explicitly indicates that the cell-specific reference signal and the channel state information reference signal are transmitted from the same antenna port.