Proposals on remaining issues on PDCCH structure 3GPP TSG RAN WG1 Meeting 90bis Prague, CZ, 9th – 13th, October 2017 Agenda item: 7.3.1.1 R1-17xxxxx Proposals on remaining issues on PDCCH structure NTT DOCOMO, INC.

Proposal on PDCCH DMRS Confirm the WA: DMRS is evenly distributed within a REG DMRS REs are #1, #5, #9 DMRS sequence is a Gold sequence as in LTE Note: in case if new Gold sequence is introduced for NR, this would be revisited DMRS sequence for NR-PDCCH can be obtained according to a reference point in frequency domain. The sequence is generated from the lowest PRB of the CORESET, and the length is equal to the number of PRBs between the lowest and the highest PRBs of the CORESET. The seed depends on the OFDM symbol of the CORESET.

Proposal on wideband RS for PDCCH Confirm the WA with the following clarifications: For a CORESET, precoder granularity in frequency domain is: Configurable between i) equal to the REG bundle size in the frequency domain; or ii) equal to the number of contiguous RBs in the frequency domain within the CORESET For ii), DMRS is mapped over all REGs within CORESET. RAN1 assumes that CORESET for PDCCH scheduling RMSI can be configured with Option i) In Option ii) UE may assume DMRS is present in all REGs within the set of contiguous RBs of the CORESET where at least one REG of a candidate is mapped.

Proposal on PDCCH DMRS Whether to conform the working assumption? For a CORESET, precoder granularity in frequency domain is: Configurable between i) equal to the REG bundle size in the frequency domain; or ii) equal to the number of contiguous RBs in the frequency domain within the CORESET For ii), DMRS is mapped over all REGs within the CORESET.

Issue 0: Wideband RS - Discussions Parameter Value Carrier Frequency 4 GHz Control Resource Set Bandwidth 18 MHz Sub-carrier Spacing 15 kHz DCI Payload Size 20 bits + CRC Modulation QPSK Channel Coding Polar code with CRC-aided list-8 decoder; 19bit CRC Aggregation Level 8 REG bundle size 6 REGs per bundle Number of OFDM symbols for NR-PDCCH 1 Channel Model TDL-A 30ns; TDL-B 300ns; TDL-C 30ns; TDL-C 300ns; 3kmph UE speed gNB antenna configuration 2Tx UE antenna configuration 2Rx Channel Estimation Practical with MRC Noise Estimation Ideal Transmission Diversity Scheme 1-port precoder cycling for ’inband RS’ S-CDD for ’wideband RS (65ns delay) Resource mapping Distributed transmission DMRS density 1/4 R1-1718799 (Ericsson)

Issue 0: Wideband RS - Discussions R1-17117039 (ZTE) Item Value Channel TDL-A DS = 300ns, 1000ns Speed = 3kmph Antenna 2*2 Frequency 4GHz Numerology BW = 10MHz(50RB) SCS = 15kHz DMRS overhead 1/4 Aggregation level 8 CCE size 6 REGs per CCE Bundle size 3/6 Payload size 20+16(CRC) Transmit scheme sCDD Mapping scheme Interleaving CORESET duration 3OFDM symbol(s) Coding TBCC Channel estimation MMSE

Issue 0: Wideband RS - Discussions R1-17117822 (CATT) Parameter Value   NR LTE Channel TDL-C-1000ns System BW (RBs) 10 MHz CORESET BW 50 CORESET duration 2 CFI = 2 Number of TX ports 1 2 CRS ports Tx Diversity 1 port with precoder cycling SFBC Antenna configuration 2Tx 2Rx AL 2,4,8 CCE-to-REG mapping Time-first mapping, LTE PDCCH interleaver DCI size 60bits+16bits CRC DMRS density 1/4 REG bundling size 6 For 6 BS: 3 in freq, 2 in time Precoder granularity REG Bundle size in frequency domain; Wideband RS

Issue 0: Wideband RS - Discussions ZTE comments: 1: SINR of -6dB is achievable even without wideband RS 2: Wideband RS consumes more energy 3: Wideband RS creates more inter-cell interference 4: Wideband RS makes resource sharing b/w PDCCH and PDSCH more difficult 5: Wideband RS makes beam-forming/multiplexing more difficult