How to check pmi unity matrix?

5G NR
#1

Hi Experts.

For checking if I have pmi unity matrix 4x4 or not unity matrix, what UE shall report in case of unity pmi matrix?
pmi index 1?
Configuring 4x4 mimo layers and UE reports ri 4 with bum of layers 4 so what shall be pmi index (i.e. unity matrix index)?

#2

UE never reports PMI matrix.
It reports some indices i11 i12 i13 and i21, check sharetechnote page for this.
So it does not report a matrix but some indices.

#3

Yes, UE reports x1 x2 for pmi.

What are pmi i1 i2 i3 i21 shall be in case of unity matrix 4x4?