Testing 5G MIMO Beamforming

Hi guys,
Anybody know how exactly testing MIMO 5G beamforming funtionality working in the field and how we can prove it through field results?

Do a Drive Test 120 degree H and 30 degree V and see if you have good throughput from same PCI.
Rsrp should not decrease by more than 3 dB within the grid of beams that is 120H and 30V.
Assuming there is line of sight all the way SSB RSRP should not decrease in average more than 3dB.

Which feedbacks can prove this in logfile?

SS RSRP will give you the coverage of the cell/PCI.

Does we have something on TEMS to check for beam indexes?
How we would know if really beamforming of 16 or 64 ports is working?

Yes, You can check it from L3 rrc reconfig msg -> ssb-positionsInBurst.
Total 8 bits for sub6 Ghz, each bit represent one ssb id.
Or from L1 serving beam management will show the serving beam with its detected beams.

You may check for PCI -SSB ID combinations.
The number of SsB Ids for each sector (small cell) 8 ,64 etc gives the number of SS beams for the 5G cell, which will be synched after beam tracking beam sweeping etc

If Qualcomm chipset UE is used you will get these from Qualcomm tree.

Ctrsy : Xcap

hope this will be helpful for you
Below is the rrc-reconfig message where you will find no.of SSB beams in SSB burst
ssb-PositionsInBurst : mediumBitmap
mediumBitmap : 10000000
[0 ] : 1
[1 ] : 0
[2 ] : 0
[3 ] : 0
[4 ] : 0
[5 ] : 0
[6 ] : 0
[7 ] : 0
For No of ports used by the UE, based on the UE capability, like
If the UE capability includes a configured CSI-RS(maxConfigNumberPortsAcrossNZP-CSI-RS-PerCC 16, example from the UE capability info) it gets configured to use the highest number of port supported. For example: 4, 8 and 32 ports configured in cell, here UE capability supports up to 16 ports. In this case, UE should get 8 port configuration.

Check csi-MeasConfig from rrc-reconfig message you will find the details about it.
For your information
Just check nzp-CSI-RS-ResourceToAddModList in this Resourcetoaddmodlist, we have resource id mappings like nzp-CSI-RS-ResourceId(from 0 to 3 its TRS info, as we define TRS using the CSI-RS resources) and also check nzp-CSI-RS-ResourceId 4 is exits for NZP CSI-RS where you will get the configured no of ports.

example from rrc-reconfig
nzp-CSI-RS-ResourceId : 4
frequencyDomainAllocation : other
other : 000011
[0 ] : 0
[1 ] : 0
[2 ] : 0
[3 ] : 0
[4 ] : 1
[5 ] : 1
nrofPorts : p8
firstOFDMSymbolInTimeDomain : 5
cdm-Type : cdm4-FD2-TD2
density : one

You can match the above with TS38.211 Table CSI-RS antenna ports, density in frequency and CDM type table.

1 Like

Hello Ameen, i need to enable max number or TRS for FR2 by so the number of configured TRS resource sets per CC is determined by related UE capability (this as NW config),
which parameter exactly from UE capability show the capability ? also how can i verify from RRC reconfiguration ? which parameter