1. WF on specification-based enhancements on CSI-RS and CSI feedback

2. Background
Goal: description of specification-based enhancements on CSI-RS and CSI feedback
Summarize the available schemes in the TR
Proposal: Capture the following description in the TR

3. Definition Non-precoded CSI-RS based schemes include the following:
a serving eNB configures CSI-RS ports that are one-to-one mapped to TXRUs, or
a static and non-UE specific (1-D or 2-D) CSI-RS to TXRU virtualization is utilized to map one CSI-RS port onto multiple TXRUs.
In this category of schemes all CSI-RS ports have cell-wide coverage.
Beamformed CSI-RS based schemes include the following:
a serving eNB applies CSI-RS port-to-TXRU virtualization

4. Schemes for non-precoded CSI-RS
A scheme is associated with codebook(s) for CSI reporting and the associated CSI reporting modes
Precoding matrix/vector for CSI reporting: 𝑾= 𝑾 1 𝑾 2
𝑾 is used for a downlink transmission hypothesis
Potential specification enhancement on CSI reporting:
PMI(s) corresponding to W1 and/or W2
If multiple PMIs are reported for W1 or W2, different feedback rate and/or granularity for the multiple PMIs may or may not be used
RI: A single RI or multiple RIs
CQI

5. Schemes for beamformed CSI-RS
A beam corresponds to one resource which a UE measures
Potential specification enhancement on CSI reporting:
Cat 1:
UE to select one or more beams from multiple beams
Report an indication of selected beam(s)
Codebook-based feedback across ports within each of the selected beam(s)
Cat 2:
eNB to transmit one beam
Codebook-based feedback across ports