MIMO & Cell Traffic in LTE
The Tx Div can be applied on all the physical channels:
- Physical DL Shared Channel (PDSCH)
- Physical Broadcast Channel (PBCH)
- Physical Control Format Indicator Channel (PCFICH)
- Physical Downlink Control Channel (PDCCH)
- The other MIMO schemes are only applicable to the PDSCH
Like the MIMO required a UE-specific feedback (RI and PMI), it is not possible to use it for all the channel.
Only the PSDCH supports the MIMO and only for UE specific data.
For example, the SIB2 is transmitted on the PDSCH but it is received by all the UE, so TxDiv. The HO command
is transmitted only to a given UE, so MIMO can be used if criterion are fullfilled.
The 3 possible transmission mode are:
- TxDiV only
- MIMO-SU Open Loop
- MIMO-SU Closed Loop
- Depending on the selected mode, some specific CQI report modes can
be configured and some specific DCI can be used