Question: do you know vendors in 5G that transmit PDSCH using same beamforming as SSB beams?
I think it’s for all.
I found this to be almost impossible.
SSB beams are not narrow enough and don’t provide enough gain for a high SINR.
Remember that SSB/PBCH are transmitted with QPSK.
There’s no way a user gets 256QAM on PDSCH with an SSB beam.
Only csi-rs beams ensure a high SINR and 256QAM.
It needs to be enabled as of now not supported.
Only SSB there to carry PDSCH.
Are you sure about all vendors that they don’t support csi-rs beams or are you saying only about Nokia?
SSB/PBCH transmitted with QPSK doesn’t mean associated PDSCH will also have same modulation.
It can be different.
Morever, for FR1, even 4 beam per sector gives around 4 dB gain (Result of on random test).
What I am saying is that using same beamformimg for PDSCH as for PBCH will not provide a high gain to use 256 QAM.
It needs narrower beams to provide a high SINR and so to use a higher MCS.
Doesn’t seems to be always correct.
In LTE even with single beam (without beamforming) we can get good SINR for 256QAM, so why not with 4 beams?
It depends on user locations.
If they could do it with asb nobody would have invented csi-rs beams with much higher gain and much narrower beamwidth.
Is it TM8 or TM7?
I mean CSI-RS beam always gives good benefit.
No doubt about that.
But PDSCH with SSB beam is also possible and gives good result, this I want to say.
This is true if we don’t speak about deep indoor coverage and higher throughput.
With SSB beams for PDSCH I think the area for 256 QAM is very much limited compared to csi-rs beams.
It does exist but is reduced.
That is true.
This is where different vendors make a difference…
It is TM8.
I have seen slides with csi-rs beams on Huawei presentations.
They use it but not sure if on all bands and all AAUs.
Huawei ahead for csi-rs beam.
Interesting to see trial…
Is it FR1?
Actually not sure if FR1 because i saw some slides for mmwave.
But frequency was mentioned 3.5 GHz.
There were 64 csi-rs beams.
Again confusion FR2… it seems csi-rs beams vendor proprietary.
What i know:
For FR1 we have 8 ssb beams ,1 ssb = 4 csi-rs beams
For fr2 only 64 ssb beam no csi-rs beams
Is it correct?
There is no mandatory rule that 1 ssb = 4 csi-rs beams.
This is just vendor implementation.