WF on transmit diversity for DFTsOFDM 3GPP TSG RAN WG1 Meeting RAN1 #88b Spokane, USA, April 3-7, 2017 Agenda item: 8.1.2.1.5 Document for: Decision R1-170XXXX WF on transmit diversity for DFTsOFDM Mitsubishi Electric, Qualcomm, Interdigital,…

Background RAN1#NR AH#1 RAN1#88 For PUCCH in long-duration, DFT-s-OFDM waveform is supported. For PUCCH in long-duration, transmit antenna diversity is supported. RAN1#88 For DFT-S-OFDM, following schemes can be candidates for UL diversity schemes for UL data: CDD, precoder cycling, antenna port switching, SFBC, and STBC. RAN1 should down select them in WI phase. FFS the corresponding spec impact (if any) For DFT-S-OFDM based transmission PRB bundling size is the whole scheduled bandwidth if the scheduled bandwidth comprises a single cluster.

Background Transmit diversity increases the link reliability in DFTsOFDM for both data and control Rank 1 transmission, link budget limited, unreliable or absent channel information Low PAPR Alamouti schemes able to operate with any number of DFTsOFDM symbol were proposed (SC-SFBC, SS-STBC, STBC) R1-1704814, R1-1705078, R1-1704813, R1-1705578, R1-1705521, R1-1705049

Background Frequency-domain precoder-cycling is not fit for DFTsOFDM PRB/PRG cycling is PAPR destroying RE-based cophase cycling (1/2 symbol LD-CDD) has limited performance gain (R1-1704814) Time-domain antenna/precoder switching has high DM-RS overhead (1 DM-RS per antenna/precoder) and poor performance at medium/high speed (no time-domain interpolation) (R1-1704814) At least for long PUCCH, Alamouti-based transmit diversity overperforms CDD R1-1704813, R1-1705578

Proposal For DFTsOFDM in data and control channel, the following schemes are candidates for transmit diversity: Low PAPR Alamouti-based transmit diversity, short delay CDD