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summary of the agreements by topic. No need to mention CRs.
Summary of Agreements by Topic:
1. Introduction of 1024-QAM for NR Downlink (DL):
- Adoption of LTE 1024-QAM Constellation: For
supporting 1024-QAM in NR downlink, the LTE 1024-QAM constellation is
adopted.
- Modulation Schemes: 1024-QAM is added to the list
of supported modulation schemes for NR downlink, alongside QPSK, 16QAM,
64QAM, and 256QAM.
2. RRC Signaling:
- New RRC Signaling: Introduced to indicate the use
of 1024-QAM CQI and MCS tables.
- Configuration Details:
- RRC signaling for 1024-QAM MCS table is present only in
PDSCH-config.
- Separate RRC signaling is used for DCI formats 1_1 and
1_2 if both are supported.
- If mcs-Table-r17 is set to ‘qam1024’ in PDSCH-config, the
UE uses the 1024-QAM MCS table for PDSCH scheduled with DCI format 1_1
(CRC scrambled by C-RNTI or CS-RNTI).
3. CQI Table Updates:
- Reuse of LTE CQI Table: The LTE CQI table is reused
with updated entries for 1024-QAM.
- Efficiency Updates: For CQI index 14, the spectral
efficiency value is slightly updated from 8.3321 to 8.3301.
- New CQI Entries: Two CQI entries are added for
1024-QAM:
- CQI index 14: Code rate 853, Efficiency 8.3301.
- CQI index 15: Code rate 948, Efficiency 9.2578.
4. MCS Table Updates:
- Five-Bit MCS Table: A five-bit MCS table with
1024-QAM entries is adopted.
- Changes to 256-QAM MCS Table: Five explicit MCS
entries (indices 2, 4, 6, 8, 10) are removed from the NR 256-QAM MCS table
and replaced with new entries for 1024-QAM.
- New MCS Entries for 1024-QAM:
- Code rates: 805.5, 853, 900.5, 948.
- Efficiencies: 7.8662, 8.3301, 8.7939, 9.2578.
5. Text Proposals for Specifications:
- TS 38.201: Updated to include 1024-QAM in the list
of supported modulation schemes.
- TS 38.211: Reflects the agreed 1024-QAM
constellation and modulation order (10).
- TS 38.214: Updates include:
- TBS determination for subclause 5.1.3.2.
- PT-RS determination for subclause 5.1.6.3.
- Per-cell data rate constraint for subclause 5.1.3.
6. Simulation Assumptions:
- Parameters for Link-Level Simulations: Companies
are encouraged to use the following assumptions:
- Carrier frequency: 3.5 GHz, SCS: 30 kHz, System BW: 100
MHz.
- Channel model: AWGN, CDL-B or CDL-C with up to 30 ns
delay spread.
- UE speed: 0 km/h, 3 km/h.
- Antenna configurations: UE (1T4R, 2T4R, 4T4R), gNB
(32T32R, 64T64R, 2T, 8T).
- Coding rates for 1024-QAM: 0.70, 0.75, 0.80, 0.85, 0.90,
0.925.
- DMRS type: Type 1, Number of DMRS symbols: 1.
- Scheduled RBs: 273.
- PDSCH mapping: Type A, Start symbol 2, Duration 12.
- Rank: Rank 1, Rank 2.
- Metric: Crossover SNR at transition points between
256-QAM and 1024-QAM.
7. Coordination with RAN2 and RAN4:
- LS to RAN2 and RAN4: RAN1 decisions on 1024-QAM and
related RRC parameters, CQI/MCS tables were communicated to RAN2 and RAN4.
This summary consolidates the agreements across different
aspects of the introduction and support of 1024-QAM for NR downlink.