Joint transmission of CSI-RS for channel state feedback and transmission point selection

An apparatus for wireless communications by a transmission point (TP), comprising:

• a transmitter configured to:
• coordinate with one or more other TPs to jointly transmit a channel state information reference signal (CSI-RS) to a user equipment (UE), wherein the coordinating comprises determining a virtual antenna port mapping, wherein each of the plurality of TPs have different antenna port mappings configured to allow disjoint precoding matrix indicator (PMI) or channel quality indicator (CQI) feedback, wherein the virtual antenna port mapping comprises at least one matrix and one or more sets of PMI restrictions, and wherein the virtual antenna port mapping forces feedback for a particular TP;
• and
• signal a reporting restriction, based at least in part on the one or more sets of PMI restrictions, to the UE, the reporting restriction indicating a limited set of PMIS that may be reported by the UE;
• a receiver configured to receive PMI feedback from the UE based on the jointly transmitted CSI-RS and subject to the reporting restriction;
• and
• a processor configured to select one or more of the TPs to serve the UE based on the PMI feedback and the reporting restriction.

An apparatus for wireless communications by a transmission point (TP), comprising:

• means for coordinating with one or more other TPs to jointly transmit a channel state information reference signal (CSI-RS) to a user equipment (UE), wherein the coordinating comprises determining a virtual antenna port mapping, wherein each of the plurality of transmission points have different antenna port mappings configured to allow disjoint precoding matrix indicator (PMI) or channel quality indicator (CQI) feedback, wherein the virtual antenna port mapping comprises at least one matrix and one or more sets of PMI restrictions, and wherein the virtual antenna port mapping forces feedback for a particular TP;
• means for signaling a reporting restriction, based at least in part on the one or more sets of PMI restrictions, to the UE, the reporting restriction indicating a limited set of PMIS that may be reported by the UE;
• means for receiving PMI feedback from the UE based on the jointly transmitted CSI-RS and subject to the reporting restriction;
• and
• means for selecting one or more of the TPs to serve the UE based on the PMI feedback and the reporting restriction.

A non-transitory computer readable medium, comprising instructions for:

• coordinating with one or more other TPs to jointly transmit a channel state information reference signal (CSI-RS) to a user equipment (UE), wherein the coordinating comprises determining a virtual antenna port mapping, wherein each of the plurality of transmission points have different antenna port mappings configured to allow disjoint precoding matrix indicator (PMI) or channel quality indicator (CQI) feedback, wherein the virtual antenna port mapping comprises at least one matrix and one or more sets of PMI restrictions, and wherein the virtual antenna port mapping forces feedback for a particular TP;
• signaling a reporting restriction, based at least in part on the one or more sets of PMI restrictions, to the UE, the reporting restriction indicating a limited set of PMIS that may be reported by the UE;
• receiving PMI feedback from the UE based on the jointly transmitted CSI-RS and subject to the reporting restriction;
• and
• selecting one or more of the TPs to serve the UE based on the PMI feedback and the reporting restriction.