Spreadtrum · 10.5.2.1

Spreadtrum proposes largely inheriting the NR PDCCH structure (CORESET, CCE, REG, REG bundles, hash functions) as the baseline for 6GR, requiring REG to consist of one RB in one OFDM symbol to avoid resource fragmentation. They require supporting only QPSK modulation for 1-stage DCI due to robustness and BD complexity concerns, while proposing further study of higher-order modulations only for 2nd-stage DCI in a 2-stage DCI structure. They propose studying longer CORESET durations beyond NR's 3-symbol limit to address capacity and coverage for IoT devices with narrow bandwidths, and support time-first REG indexing within CORESETs. Spreadtrum requires defining upper limits on monitored PDCCH candidates and non-overlapped CCEs per slot, applied to all device types, and supports only slot-based monitoring capability while rejecting span-based and slot-group-based monitoring to reduce implementation complexity. They propose transparent MU-MIMO transmission via overlapping CORESET resources with different DMRS scrambling IDs, and require studying PDCCH repetition for reliability enhancement as well as transparent or non-transparent time-frequency resource sharing between 5G and 6G CORESETs for MRSS coexistence.

Spreadtrum proposes inheriting NR PDCCH physical structure (CCE/REG/REG bundle framework, ALs 1/2/4/8/16, time-first REG mapping, hash-based search space) as baseline for 6GR. They prefer one port precoder-cycling between REG bundles for transmit diversity over SFBC, arguing comparable performance with simpler implementation. They propose studying longer CORESET duration (4/6/12 symbols) to address capacity in hotspot areas and coverage for narrow-bandwidth UEs. They require a unified framework for sub-slot/slot/slot group-level PDCCH monitoring to replace three separate monitoring capability types from NR, reducing UE and gNB implementation complexity. They propose studying a harmonized PDCCH monitoring adaptation mechanism, criticizing NR's overlapping functionalities (PDCCH skipping, SSSG switching, DCI format 2_6, PEI, LP-WUS) and suggesting alternatives like two-stage DCI or dynamic candidate indication by LP-WUS.