For NR does UE report SRS always?
Or we need specific parameter to enabled it?
I’m thinking with SRS does UE measure CSI-RS signal to report csi or srs used only for channel estimation?
gNodeB can decide anytime to switch between srs weights and csi-rs (pmi) weights.
In all logs I see srs configured.
Ok what srs 2T4R indicates?
Srs UE periodicity I remember in LTE we have parameter and actsrs as well to activate srs reporting.
Association between SRS ports and UE antenna ports for 2T4R:
More details here: 5G - Frame Structure - 5G | ShareTechnote
One of friend told me with srs reporting throughput degradation seen in NR.
Not sure why srs need always if we are applying precoding using csi only ie fixed weights.
Case for SU-MIMO.
srs offer better accuracy than csi-rs.
So higher gain with srs weighting.
Huawei uses srs almost all time.
Till uplink sinr of srs is below -15 dB !
So weights are 99% of the time based on srs measurements in uplink.
But srs weights require lot of baseband processing compared to pmi weights.
Yes agree I know srs will use once we have MU-MIMO. In NR.
As AoA driven only from srs.
Good discussion. one question for NR SRS if UE is reporting SRS to gnodeb what metrics are used in gnodeb ? Is there any thing like RSRP or SINR for SRS signals in uplink?