Number of layers for Aggregated Carriers

Hi All,
For LTE CA for band combination, what max MIMO layer IE indicates I’m getting error for 3 CC CA?
Any way to identify number of layers for Aggregated Carriers?

Hi All,
Number of layers per CC is in DCI.
You won’t see it in RRC layer 3 messages.

But for UE capabilities (band combination what max mimo layer IE indicates) you can check

Ok thanks. :+1:
I think with tm3 I need to reduced no of layers, from 4 to 2.
Aggregated combo exceeding max.

With every CA combination what max layer UE can support is part of UE capability?

I find for band 3 CA bandwidth class is C with supported MIMO capability 2 layers.
Does it mean for band 3 with 2 carriers I can’t use tm3 with 4 ports?

TM3 is transmit diversity. It is always supported.

Tm3 transmit diversity?

My query is that for both carriers, can I use 2 layers so it sum up to 4 layers?
As supported MIMO capability DL is 2 layers.

Ohh sorry. My bad.
I mean TM3 TM4 both can have Tx diversity.
And 2 layers can be use with both TM3 and TM4.

Layers are per carrier.

Ok got it!
So per carrier I can use 2 layers only.

2 carrier aggregated doesn’t mean 4 layer.

Not beyond 2 can I use?

When your in CA mode, THEN you cannot use more than 2 layers.
Without CA your layer support can be 4.

Ok let me put this way:
With supported MIMO DL capability as 2 layers with bandwidth class C.
It’s clear I can use 2 CC, i.e. intra band contiguous as it’s in item 0.

Now my query: can I use in CA mode for each carrier 4 layers?
With above mentioned condition.

No, you can’t.

Ok now clear.
That’s why my CA getting failed a s someone uses 1 carrier using 4 layers, 2 with 2 layers.
So it’s exceeding max layers condition.

But CA should not get failed, rather carrier having 4 layer should change to 2 layers, shouldn’t it?

No it’s not happening as UE consider config given by network for 4 layers on pcell, then scell 1 having 2 layers, so as per UE capability it’s exceeding max layers condition.

This is weird.
There will be many UEs with 2 layer possibility, and network can have 4 layer.
So do you mean CA will be failed for all such UEs?

Yes one of prominent reason.

I am still in doubt.
Even though Pcell is configured with 4 layers, for THAT ue eNB will only scheduled with 2 layers.