Seems no network deploy tm9 due to high overhead of CSI-RS.
I don’t see many document about DMRS, CSI in LTE.
Please remember DMRS introduced in LTE in DL with tm8 mode, i.e. 3gpp rel9.
DMRS in UL there from 3gpp rel8.
Csi-rs introduced in LTE with 3gpp rel10, i.e. tm9 mode.
This is as per 3gpp:
Transmission mode 8 allow 2 UE to simultaneously benefit from dual layer beamforming, i.e. total of 4 layers can be transferred. Alternatively, those 4 layers can be used for single layer beamforming towards 4 UE. Dual layer beamforming allows throughputs to be doubled relative to single layer beamforming. Thus this transmission mode supports a combination.
I don’t deny, but what is your antenna config? Is it 8T8R?
As per Huawei, minimum requirement is 8T8R.
Ok, let me check any specs mentioned it.
Any operator(s) in the world using TM9 in 8T8R systems in commercial MBB (not FWA) networks? What is the penetration rate of TM9 capable terminals? Back in February 2020 GSMA said “Mainstream chip vendors, such as Qualcomm, HiSilicon, and MediaTek, have launched TM9 terminal chips. Since 2018, TM9 has been activated by default on 20 new terminal models, covering five mainstream vendors.” However GSA Gambod only returns 13 models all of them being are Outdoor CPEs for FWA. I am aware of 4 handsets: Xiaomi Mi10 Global; Oneplus 8; Sony Xperia 1; Huawei P40Pro (fgi 108 = true). Appreciate if you add a couple more to the list!
Hi @Oleg_Leonov ,
In my view, TM9 deployment worldwide very less. Even most of operators in USA already disabled TM9 in network - it was leading to network issues.
As TM9 work with CSI-RS, which consumed RE meant for PDSCH so lowering throughput as well.
We have option with TM9 as 2, 4, 8 CSI-RS.
Appreciate your quick response, Ankur. Does TM9 provide gain over TM3/TM4 in 16T16R and higher order systems? Is there a break-even point on the MIMO order scale, where TM9 becomes effective?Which modes are used in existing Massive MIMO deployments? TM7, TM8 and TM9? How about TM10 - does it even exist in reality?
TM9 is from 3gpp rel 10.
In Nokia, it has counters measuring UE category, Huawei does not have.
So by Nokia OSS, we can quickly estimate ratio of rel 10 and later UE, for tm9 detail it should be check by FGI bit.
Huawei FMA tool can analyse.