Rank 2 % formula

Can anyone share the Rank2% formula with TM4(close loop MIMO) for the huawei network, if i calculate by Rank2% by the below mentioned formula, the % of Rank2 decreased when i enable close loop MIMO (TM4) in the network as compared to open loop MIMO (TM3).
RANK 2% =100*L.ChMeas.RI.Rank2/(L.ChMeas.RI.Rank2+L.ChMeas.RI.Rank1)


How much is the decrease?
How is throughput?

No big change in DL user throughput but prominent reduction of Rank2 utilization.


How is ratio of qpsk/16-64-256qam trend?

64QAM/16QAM improved.

This is due to TM4 gives better channel quality than TM3, TM4 has PMI feedback.
Enodeb can schedule with 1 layer but higher mcs, it can improved better channel estimation than TM3 with 2layers.

Dear Hainm, but the question is why rank2% is decreased or the formula to calculate the rank2% is different in TM4.

For eg: enb need to transfer X bytes data to UE in TTI.
Using TM3, it need 2 layers with mcs10.
But TM4, only need 1 layer with mcs20.
Can you check trend of bler?

Hainm, IBLER increased because i made some other parametric modification on cell but my concerned is about R2%

Rank2 % reduced after changed TM3 to TM4 is normal. Throughput is depended on not only Rank, also cqi/mcs.

Hainm, Thanks, Do u have any idea to improve R2% by parameter tuning?