In the figure total 4 antennas are shown but are not explicitly mentioned as TX or RX.
What I noticed in 5G drive test is that UE is challenged a lot for SRSR.
Most of the time it stays at max power 24.5 dBm.
Then is the PUSCH power.
Then PUCCH power is less challenged.
So it can act as TX or RX at mentioned configs, right?
Yes for SRS, not for PUSCH.
For PUSCHUE will use only 2 antenna among the 4 existent one.
Yes, OK.
Where can you get SRS power IE?
I never checked it…
In probe logs.
And gNodeB can handle SRS UL SINR up to -20 dB values!
Which UL message?
Here’s how it looks in time from a UE log:
Those are internal measurements of UE are not in any protocol to be reported like layer 2, layer 3 or layer1.
Understood.
Looks like 5G UE battery draining due to high SRS power.
SRS power is always high, for weight calculation.
But SRS periodicity is normal 40 ms.
My understanding is this:
UE has 4 RX antenna.
Among those 4 RX antenna 2 can be used for TX as well (for PUSCH).
But those 2 antenna are fixed, meaning the UE can’t do antenna selection for TX.
It has 2 fixed TX antenna.
But in your figure ant0,1, 2 were used for 1T and 2T may be not same UE?
That picture is for SRS.
SRS can be transmitted from all 4 RX antenna.
But PUSCH only from 2 antenna.
Ok, thanks.
Let me be more clear by example. let’s say antenna has 4 rx ant A, ant B, ant C and ant D.
UE can receive data in ABCD, can transmit SRS on ABCD, but can transmit PUSCH only on BC ( let’say).
That means UE cannot do antenna selection for TX in uplink like this: UE can send data in this slot on PUSCH on BC antenna, next slot PUSCH cannot be sent on AD, next slot cannot be sent on AC, next slot cannot be sent on AB and so on. Only on BC antennas the pusch can be sent.
Ue can transmit PUSCH only on BC and that’s it for 2x2 UL MIMO on PUSCH .
So all the time PUSCH data can be sent on antenna B and antenna C.
So no diversity for TX antenna selection in uplink in case of 2x2 UL MIMO.
But SRS can be transmitted from any antenna ABCD.
To summarize: UE receives data on antenna ABCD, UE sends srs on antenna ABCD, UE sends PUSCH data only on antenna BC.
Yes, but where is this antenna selection criteria mentioned.
BC is just an example.
Could be as well fixed AC.
Or fixed AD.
Idea is that TX antenna are fixed.
Cannot be changed for diversity on TX.
If UE has 4 RX antennas, when CA 2CC, it can support max 2 layer per each carrier, right?
Or UE can support 4 layers * 2 carrier.
Hi Experts.
We often see UE power capability is 23 dbm.
If UE has 4 Tx antenna, 23 dbm is power of each antenna or all antennas?
Do you mean LTE or NR?
For new phones there is DPS dynamic power sharing between LTE and NR.