TM9 is for multi user MIMO where as TM4 for single user MIMO.
Also TM4.
So the only difference is that TM9 can send csi- rs while TM4 send crs, right?
TM9 supports 8 layer beam forming where as TM4 doesn’t support.
As I know, only 4 layers.
Even TM9 support 4 layers.
Yes, but I am talking about 8 layer beam forming.
I read TM9 having 30% more cell throughput compared to TM8.
Csi-rs introduce with TM9 mode in LTE.
Option are 1, 2, 4, 8 csi-rs.
In NR max 32 csi-rs ports.
And there are vendors using 32!
Yes for NR at max 8 ports used but no TM modes in NR.
What is the difference between csi-rs and crs?
Cell specific reference signal used for cqi, rsrp measurements.
Csi-rs used with tm9 for cqi measurement, ri, pmi.
Csi-rs play wide role in NR.
No CRS in NR.
Even csi-rs used for mobility in NR.
So, it’s almost same, right?
DCI changed to 2 new references as Channel State Information Reference Signal (CSI-RS) and Demodulation Reference Signal (DMRS) in TM9, if I remember.
DMRS introduced with TM8 in DL with PDSCH.
Earlier no DMRS in DL for LTE.
It’s used for better channel estimation for LTE in DL alongwith beamforming concept.
TM8, TM9 mainly but some RE used by DMRS so overall throughput will be impacted as seen.
For NR we have 32 csi-rs port. Anyone seen such network configuration? I seen max 8 ports used.
Yes, I have seen 32 in NSA.
Will 32 csi-rs port impact capacity?
How many slots/RE used for RS?
32 csi-rs ports will impact SINR and better coverage (indoor penetration) and sharper beams.
Also is suitable for MU-MIMO for better user pairing.
32 is the maximum number of ports supported.
The actual used number depends on the number of UEs served and antenna.
CDM/FDM to multiplex the reference signals is possible so the overhead is reduced.
How can we say this solution 32T32R massive MIMO however we have 16 streams per sector (4 cells split using 4T4R)?