Rank Indicator LTE Huawei

[paulus]

Hi all,

Just wondering to know can anyone share how to calculate rank indicator 2 ratio in LTE Huawei?

As I know, rank indicator 2 means there is no interference/No correlation (Orthogonal) to each other of multiple antenna in MIMO system.

If rank indicator 1, it implies that the signal from the two Tx antenna is percieved by UE to be like single signal from single Antenna, which means the worst

performance.

For Example, in my network, we got a filter correction that if rank2 ratio is < 50%, this means the MIMO system expereince low rank indicator 2, but I don't

know which counter to calculate this ratio, I'm still new in LTE.

I'd be grateful if smb can answer my question


Thanks
Br//Paul

[paulus]

Hi Guys,

Here is the counter..

L.ChMeas.RI.Rank2 & L.ChMeas.RI.Rank1

Attached is the calculation. The lower of the ratio (<50%), we can say it's critical.

Please correct me if i'm wrong


Thanks
Br//Paul

[jbada]

Hi Paulus

Yes you are correct in your network only 50% of time is in MIMO SM. the rest of the time is in TX diversity. It's not critical but you can improve with optimization task to 60%.

[paulus]

Hi Jbada,

Thanks for your response.

How do we improve it through parameter adjustment? Is there any parameter we could change?

Thanks
Br//Paul

Hi Paulus

Yes you are correct in your network only 50% of time is in MIMO SM. the rest of the time is in TX diversity. It's not critical but you can improve with optimization task to 60%.

[desi_larka]

hi Guys

Can the people from Different network answer , what is the typical RI=2 in their network at network level

I am seen typically around 65 to 70% RI=2 in Huawei , Nokia , E*******.

Can anyone else comment

NETWORK : INDIA
OPCO NAME : xxxx
RI=2 % VALUE at OSS Level : 65 to 70%

regards

[Shid]

Hi all,

rank1 -> enodB ask UE to use Tx Diversity
rank2 -> endeB ask UE to use Spatial multiplexing ( will get benefit of MIMO )

mostly low rank2 due to installation still not proper,

step to do troubleshoot :
1. check mimo related parameter
2. check x-feeder or not
3. do cross jumper to see if the problem comes from jumper
4. change antenna

in our network we categorized as WPC rank2 if the rank2 ration less than 20%

CMIIW