5G UL Reference Signals: (SRS) Sounding Reference Signal Optimization 

حبيبي يا بيلو 😘

Hi Georgios, I didn’t find any related information to confirm your question. I will let you know here if i find any You can refer to 5G NR in Bullets page 365 to 367. It covers all the information regarding antenna switching

Generally looks like so, having more diversity with higher Rx config.. seems the latter would be efficient

Hi georgeioskarouzos, Yes you are perfectly correct; you can find the clear procedure explained in pictures in 5G NR in Bullets book, Page 379 for Codebook based transmission and Page 380 for Non-CodeBook based transmission.

Thank you very much Mohamed.

@@georgioskarouzos7418 Thanks to you for letting me also review this information through sharing your valuable information and feedback

The deep detail about it still also not very clear to me; It is a combination of code multiplexing and allocating different cyclic shift; i am trying to check different sourced to further clear the concept of cyclic shift. I will let you know if i reach into something

Thanks alot, Navas

Hi Vipin; the question is not very clear to me; it seems I am missing something; we can have a one-to-one chat on Linked In to figure out the question and answer

Umm mm please if you could answer? Thanks

Hi man, no worries, it is the same concept as the DL, if there is a less power used by the bts the downlink coverage will be weak and probably the coverage demodulation process from the UE will result in reporting a poor CQI and as a result it will impact the link budget process in general which will result at the end in low Mcs, etc. the uplink is the same around, assume the UE is at cell edge the transmitted power of SRS might be insufficient accordingly this will still negatively impact the complete process as explained in downlink; as a summary improving SRS coverage will result in more accurate beam forming, higher mcs especially for EDGE users

@mohamedeladawiashour okies gotcha :) thanks .. I was looking from a different perspective, other than the obvious ... Thanks once again. 🙏

@filthykid84 welcome anytime mate

Materials added to the below link. thank you www.mohamedeladawi.com/5g-ul-reference-signals-srs-sounding-reference-signal-material/

As per my my understanding yes, it can’t support UL 2X2 MIMO as long as number of Tx branches is less than 2

a little update: checked a live network log, UL 2x2 MIMO can be used by UE when the capability is supportedSRS-TxPortSwitch=1T4R. In the RRCReconfig message, pusch-Config setup IE {txConfig codebook, maxRank =2}，and related srs-ResourceId{usage codebook, nrofSRS-Ports ports2}, then UE send out srs via 2 Tx (fixed conifured by RF), gNB set precoder layer=2 in DCI after few frames. @@mohamedeladawiashour

Hello, based on my limited knowledge, CSI is essential for DL due to two main reasons: 1- Not all UEs support antenna switching, which is a prerequisite for using SRS for DL channel estimation. 2- CSI provides better performance for EDGE users compared to SRS.

Thanks, a lot, i believe it is designed to be at the last 2 as SRS usually start special slot where it has Dl/GP/UL, so it should be at the end after the guard band symbols; regarding CSI RS, the video session should be ready by 29~30 of JUNE2023.

Hi Vipin, You can find the working materials at the below link. Regarding your question, The UE transmits the SRS from each receive antenna www.mohamedeladawi.com/5g-ul-reference-signals-srs-sounding-reference-signal-optimization/

@@mohamedeladawiashour thanks..in this video it was told that in case of 2t4r srs is transmitted using receiver….??? Why .. tx means at UE side is transmitter correct? Or tx means tx from gnb side??? Have confusion please clarify

Hi, it looks kind of complicated but whatever mentioned it is about the UE side; Antenna switching means the UE is capable of switching the transmit paths between ue receive antenna; refer to page 365 and 366 in 5G NR in bullets for more details.

@@mohamedeladawiashour thanks ..please make one more video that clears such doubts thanks in advance

Yes it can be used, as per my understanding

@@mohamedeladawiashour thanks one more query it's written that for 1T4R case srs resources set could be zero or two..then what does it mean? Because at least one resources set should be there to map srs resources correct so confusing terminology zero or two..plz help

Hi Vipin, it is mentioned where? Speaking about 1t4R antenna switching, you should have two resource set id each will have 2 srs resources, have a look into page 366 in 5G NR in bullets book

@@mohamedeladawiashour yes for aperiodic case it is mentioned that zero or two..plz refer( I am unable to attach that link sorry) srs 5g sharetech note ..in that 1T4R aperiodic config

Hi vipin, i will have a look into and i will get back to you

I cant agree more; i have to consider this part more in any new video

Hi; antenna switching is related to UE capability and it is working whenever you activate the advanced SU MIMO from gNB side and when the UE support antenna switching

Where can we find some example on antenna switching?

Most welcome, you can find the working materials at the below link www.mohamedeladawi.com/5g-ul-reference-signals-srs-sounding-reference-signal-optimization/

Thanks, Farshad. I do agree; I need to slow down a bit

I agree; i am considering to slow down; it is getting out of control sometimes but i am working on it

Hi; yes i agree; i was going very fast in this specific video; i tried to slow down since this video. Thanks for the advice