DCI Format 2 PMI Report (LTE)
specifies the latest Precoding Matrix Indicator(s) (PMI Precoding Matrix Indicator) reported by the UE User Equipment (e.g. cell phone). The latest PMI report can be specified for PDSCH Physical Downlink Shared Channel allocations using 1, 2, 3, or 4 layers. Valid PMI reports are shown in the table below:
|
Number of layers |
2 C-RS Cell-specific RS Antenna Ports |
4 C-RS Antenna Ports |
|---|---|---|
| 1 | 0-3 | 0-15 |
| 2 | 0-1 | 0-15 |
| 3 | n/a | 0-15 |
| 4 | n/a | 0-15 |
When Format 2 DCI Downlink Control Information is used to specify PDSCH RB Resource Block allocations for a user, the eNodeB can explicitly specify the precoding that was applied to the PDSCH allocations, or can indicate that the last PMI report from the UE was used. In the latter case, the LTE Long Term Evolution demodulator needs to know what PMI that the UE reported to be able to completely decode the contents of the DCI payload as well as decode the corresponding PDSCH user allocation.
More information about DCI Format 2 can be found in 3GPP TS Technical Specification 36.212, Section 5.3.3.1.5.
See Also
