TM9 - Number of antenna at UE end and eNodeB end

RAN
1

Hi Experts,

It’s known tm9 Introduced as part of 3gpp rel 10 having 8x8 mimo mode, where csi rs reference signal introduced with ports 15 to 22 and pdsch with dm-rs with 7 to 14 ports, i.e. UE specific reference signal.

Need to understand for tm9 how many rx needed at UE end if 8 ports, 4 ports configured at antenna end.

2

Number of antenna at UE end and at enodeB end are different.
But for 8 layers UE will need 8 RX antenna.
However nobody implemented 8x8 mimo because it does not happen in the field.
For 4x4 MIMO you need 4 RX antenna.

3

Generally for tm9 we have options for csi rs antenna ports as 1, 2, 4, 8 with virtual ports 15 to 22.
But here UE specific rs ports also 7 to 14.
Like tm8 we have only 2 virtual ports 7, 8 so its clear at UE end 2 RX enough to receive 2 layers from port 7, 8.
In same way I’m thinking for UE specific ports 7 to 14 which are fixed for tm9, how UE will receive beam?

4

Let me undesrtand, is possible to configure TM9 for 4x4 MIMO or only 8x8?

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