Session 2: 5G/NR Massive MIMO Deep dive

[@srinaths2840]

Hello, Thank you for the great contents. I would like to ask the antenna explanation video link that you explained in the start of this video. Thank you in advance and God bless you and your loved ones.

[@mohamedeladawiashour]

Thanks a lot for your kind words! The link is already included in the video description. Please take a look and let me know if it’s what you're looking for.

[@ahmedelbayyar3377]

Thanks alot for sharing

[@mohamedeladawiashour]

Thank you 🙏

[@thuydo1395]

Thank you so much! Waiting for new ep!

[@mohamedeladawiashour]

Thank you

[@mohamedbelal4545]

👌👏👌👏👌👏👌👏

[@mohamedeladawiashour]

👌👌👌

[@ravi3440]

Thanks @mohamed, looking for the future ones on this topic too !

[@mohamedeladawiashour]

Thanks a lot Ravi for your feedback, next one will be published soon and it will be more about going in deep for reciprocity and codebook based for dl transmission scheme as this is the core area of the beamfoarming.

[@bnb3590]

perfect. I cannot find links for session 3,4,5

[@mohamedeladawiashour]

Thanks, i didnt upload yet.

[@georgioskarouzos7418]

Very helpful Mohamed! Two questions from my side : a) Is MU-MIMO supported with Half-band SRS, given that with Half-band SRS the SRS- capable Ues can use reciprocity based beamforming in longer distances from gNBs? b) In case of Reciprocity-based beamforming the CSI Report is sent through SRS. Is it correct? Thank you

[@mohamedeladawiashour]

Hi Georgi, Apologies for the delayed response. Regarding part (a), I believe you are correct based on my understanding. for Part(b) Not exactly. In reciprocity-based beamforming, the uplink channel state is derived directly from SRS measurements, eliminating the need for an explicit CSI report to the gNB for downlink beamforming purposes. Here’s why: In TDD mode, 5G relies on channel reciprocity, meaning the uplink channel is assumed to be reciprocal to the downlink channel. The gNB uses the uplink SRS to infer the downlink channel conditions and perform beamforming without requiring a CSI report from the UE. However, for non-reciprocity-based scenarios (e.g., FDD or when TDD reciprocity isn’t perfectly reliable), UEs generate a CSI report (e.g., including CQI, PMI, and RI) and send it to the gNB through PUCCH or PUSCH. In summary, while reciprocity-based beamforming utilizes SRS for channel estimation, the explicit CSI report is typically not sent for this purpose and the CSI report, including CQI, rank, etc., is evaluated through SRS. However, the report itself should be transmitted either via PUCCH or PUSCH whenever needed. Please feel free to correct me if you come across more accurate information.

[@georgioskarouzos7418]

Thank you very much for your valuable feedback Mohamed!!