1. 3GPP TSG RAN WG1 Meeting #90bis
Prague, Czech Republic, 9th – 13th October 2017
Agenda item:
R1-171xxxx
WF on TRS design
MediaTek, [Ericsson, ZTE, Sanechips, Qualcomm, CHTTL, Intel, Spreadtrum Huawei, Hisilicon, Samsung, vivo]

2. Proposals TRS periodicity 20ms, 40ms and 80ms are supported
TRS periodicity 10ms is additionally supported when 3 additional DL DMRS symbols is configured (HST scenario)
Whether measurements across different TRS bursts can be combined or not is configured by RRC (i.e. TRS measurement restriction)
For N=2+2, X=2, TRS symbols have the same symbol positions in the two consecutive slots
For UL-DL switching periodicity of 1 slot, consider the following options,
Option A: only one of the two slots can be transmitted in some TRS bursts, effectively reducing to N=2, X=1 in that burst
Option B: Design X=1 for this particular scenario
FFS on N in X= 1

3. Proposals DMRS and TRS are at least TDMed from UE perspective
One of the following symbol positions per slot can be configured by RRC, except for the case when 3 additional DMRS is configured
Option 1: symbol 4 and 8 ( symbol index starts from 0)
Option 2: symbol 5 and 9
Option 3: symbol 6 and 10
Note 1: Potential down selection can be done until next meeting. It is not limited to select only one option
Note 2: RRC signaling to configure TRS as above can be related to the existing RRC signaling for DMRS, CSI-RS, etc.

4. Proposal
When C-DRX is configured to the UE, then an assisting TRS burst is present at a RRC configured slot offset kTRS≥0 prior to the start of the C-DRX on duration
Note: This TRS burst is only transmitted when there is data for the UE in the C-DRX on duration
Note: kTRS =0 implies the TRS is in the first slot of the C-DRX on duration
Dynamic indication of rate matching around this assisting TRS is supported
Note: To protect PDSCH to RE mapping for other UEs scheduled in a slot containing the assisting TRS burst
Note: May use the same mechanism as dynamic rate matching around aperiodic CSI-RS

5. Proposals TRS sequence has the same formula as that for CSI-RS
FFS on c_init
Support FDM between TRS and SSB

6. Proposals TRS RRC parameter set TRS-burst-length TRS-symbol-position
TRS-periodicity
TRS-slot-offset
TRS-RB-position
TRS-port-index
TRS-sequence
TRS-QCL-source
TRS-meas-restriction

7. Appendix
The feasible TRS symbol position with St= 4 under different DMRS pattern and PDSCH region