OAI nrUE CSI-RS overlap with PDSCH issue
When testing with 3rd-party gNB for CSI-RS overlap with PDSCH case, I found below issue:
- UE will assert when ZP CSI-RS and PDSCH overlap on same slot. Although DM-RS on symbols 2/7/11, CSI-RS on symbol 8, still meet below error:
In nr_dlsch_extract_rbs() /opt/openairinterface5g/openair1/PHY/NR_UE_TRANSPORT/nr_dlsch_demodulation.c:1123
DMRS RE overlapping with CSI RE, it shouldn't happen
looking at the code below I'm not sure why we are checking DM-RS RE overlap with CSI-RS RE, they are not on the same symbol:
AssertFatal((dmrs_rb_bitmap & csi_res_even) == 0, "DMRS RE overlapping with CSI RE, it shouldn't happen\n");
AssertFatal((dmrs_rb_bitmap & csi_res_odd) == 0, "DMRS RE overlapping with CSI RE, it shouldn't happen\n");
also below code seems to have problem considering DMRS and CSI not on the same symbol:
uint32_t dmrs_csi_overlap_even = csi_res_even + dmrs_rb_bitmap;
uint32_t dmrs_csi_overlap_odd = csi_res_odd + dmrs_rb_bitmap;
- UE will not do rate-matching when NZP CSI-RS and PDSCH overlap on same slot, which caused PDSCH decoded as NACK. This does not happen with COTS UE.
Below is gNB RRC message log in pcap format:
Below is UE log (added some debug info) when ZP CSI-RS overlaps with PDSCH:
Edited by Alex Jiao