How RU cater for 16 layers with less then 16 ports?

Hi Experts,
For PDSCH antenna port mentioned 1000 to 1011 so these are 11 ports now with 8 SSB in FR1 having 8 UE 2 * 2.
How RU cater for 16 layers?

Because are poiting to different spatial directions in case of mu-mimo so some of the 12 pdsch DMRS can be reused.
Some vendors advertise even 24 layers simultaneously for mu-mimo.

In case of SU- MIMO without UE pairing its interesting to see how 8 UEs 2 * 2 served by 8 SSB beam having 16 layer.

Su-mimo means max 4x4 DL mimo as of today even if network supports 8x8 DL mimo.

Thanks for single user mimo if we have 8 ue 2x2 MIMO.
Then we required 8 SSB.
1 SSB = 2 layer
Now in 5G doc mentioned max 8 layer in theory.
Question is that how 16 layers will be cater if max we can go upto 8 layer?

8 layers max are for one user only in 3gpp.
That means it is impossible to send 12 or 16 layers to one user.
But can be sent to different users in different locations.

Yes but 2 layer per user can be possible.
I’m not saying 16 layer to single user.
In my case 8 users in cell with 8 SSB beams.
So 8*2 = 16 layer in that way.

I think it is very rare to see 8 users so nicely separated in space so can be simultaneously scheduled with mu-mimo.

Lets forget about mu-mimo.
With su-mimo it will work.
I’ve seen in mMIMO. User always scheduled per TTI.
In 5G it’s slot.

I’m not sure how many users can be scheduled per slot in 5G.
Like per TTI we can go upto 20 user in 4G.
Per slot as of now 1 user only. But not sure.

Why do you think in 5G is different?
Per slot limit is PDCCH.

No of user per slot gNB scheduled, I’m not aware.
Seen only 1 user as of now.

There was a discussion of how many layers was max scheduled in 5g amd there was several answers with max 8 layers meaning 2 users with 4x4 mimo or 4 users with 2x2 mimo.
No one has seen 12 or 16 layers scheduled simultaneously.
8 layers as seen in counters was the max value.

Ok, then it’s system limitation.

I think there are no cells with such a heavy traffic to see 12 or 16 layers.
Plus that rank 4 is seldom seen in drive tests for an UE.
Usually rank 2 and rank 3 are mostly used for one UE.

My concern is for 8 SSB with 8 user 2x2 mimo.
Seems not possible now.

Transmission scheme 1 for PDSCH with 8 layers.

@RFSpecialist, that was the question.
Transmission scheme 1 support upto 8 layers only.
What is the meaning of 64T64R or 32T32R with 16 PDSCH layer, which was discussed earlier… and 8 SSB with cross polarization can go upto 16 layers in FR1 without beam refinement.
Still not clear for me.

Thanks @Vijay_Chaudhari for highlighting it. Exactly same question I am having.
It was understood as of now we can go upto 4 SSB for FR1, so max 8 layers.
But for FR2 we have 32 SSB so how this transmission scheme 1 related with 8 layers work there another query or there is new transmission scheme for which I am not sure…

Hi @ankgitm. As per 3gpp only ts1 is available for NR.

@Vijay_Chaudhari, 64T64R means there are 64 radiating elements that forms the AAU.
But what is important is the csi-rsports that can be 4, 8, 12, 16, 24 or max 32.
This number of csi-rs ports can be seen in n1n2 IE in the rrcconnectionreconfiguration.

8 layers max is for one user. As i explained Huawei has counters up to 16 layers for MU-MIMO.