When testing with 3rd-party gNB for CSI-RS overlap with PDSCH case, I found below issue: 1. 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; ``` 2. 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: [csi_rs.pcap](/uploads/89049cab4dd6c33e999bf34e7217df4a/csi_rs.pcap) Below is UE log (added some debug info) when ZP CSI-RS overlaps with PDSCH: [ue_csi_rs_nzp-slot2_zp-slot3_pdsch-slot3.log](/uploads/5cf05189354642cd77b6632bad750bc6/ue_csi_rs_nzp-slot2_zp-slot3_pdsch-slot3.log)