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11ax CSD Design. Date: 2016-05-16. Authors:. Authors (continued). Authors (continued). Authors (continued). Authors (continued). Authors(continued). Authors (continued). Authors (continued). Authors (continued). Authors (continued). Introduction.
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11ax CSD Design Date: 2016-05-16 Authors: Bin Tian, Qualcomm
Authors (continued) Bin Tian, Qualcomm
Authors (continued) Bin Tian, Qualcomm
Authors (continued) Bin Tian, Qualcomm
Authors(continued) Bin Tian, Qualcomm
Authors (continued) Bin Tian, Qualcomm
Authors (continued) Bin Tian, Qualcomm
Authors (continued) Bin Tian, Qualcomm
Authors (continued) Bin Tian, Qualcomm
Introduction • Cyclic Shift Delay (CSD) was introduced since 802.11n • De-couple the same STF signals transmitted on multiple antennas /streams for better Rx AGC setting • Provide diversity in data field and pilot tracking • In this presentation we propose the CSD design for 11ax • Values for per antenna and per stream CSD • Details for CSD application Bin Tian, Qualcomm
Applicability of Per-Stream vs. Per-Antenna CSDs • Following 11ac design rational • Per stream CSD • Mandatory for HE modulated fields • Also applicable to pre-HE modulated fields when beam_change=0 (HE SU only) • Per antenna CSD • Mandatory for pre-HE modulated fields when beam_change=1 • Not specified for the HE portion and the pre-HE portion when beam_change=0. Can be applied as part of Q matrix Bin Tian, Qualcomm
Per Stream CSD • Propose to reuse the 11ac per stream CSD values for all HE PPDU • CSD value: [0 -400 -200 -600 -350 -650 -100 -750] ns • Harmonize the CSD values across all the modes • AGC performance difference is minor despite the duration difference between 0.8us STF (11ac and non-triggered 11ax PPDU) and 1.6us HE-STF (triggered PPDU) • For UL MU MIMO transmission, the per stream CSD value is based on global stream index • DL MU MIMO, which inherits from 11ac, already uses global stream index Bin Tian, Qualcomm
Per Antenna CSD for Pre-HE Modulated Fields • When beam_change=1, Pre-HE Modulated Fields are modulated the same way as legacy • Omni transmission along with legacy per antenna CSD • Reuse the legacy per antenna CSD values (shown in appendix) • When beam_change=0, Pre-HE Modulated Fields shall be modulated the same as HE-LTF1 • Per antenna CSD is not specified since its impact is absorbed in the Q matrix Bin Tian, Qualcomm
Per Antenna CSD Application in UL MU Transmission • In UL MU transmission, per antenna CSD application uses the local index • Number of Tx antennas is unknown to other STAs in UL MU transmission • Consistent with other modes, clean spec and implementation Bin Tian, Qualcomm
Straw Poll 1 • Do you agree to add to 11ax SFD 11ax shall reuse the 11ac per stream CSD values for all HE PPDU Bin Tian, Qualcomm
Straw Poll 2 • Do you agree to add to 11ax SFD In UL MU-MIMO transmission the per stream CSD value is based on global stream index Bin Tian, Qualcomm
Straw Poll 3 • Do you agree to add to 11ax SFD 11ax per antenna CSD in Pre HE modulation shall • reuse the 11ac per antenna CSD values when beam change =1 • not be specified (absorbed in the Q matrix) when beam_change=0 Bin Tian, Qualcomm
Straw Poll 4 • Do you agree to add in 11ax SFD In UL MU transmission the per antenna CSD value is based on the antenna index of each STA (i.e. local index) Bin Tian, Qualcomm
Appendix Bin Tian, Qualcomm
Legacy Per Antenna CSD Bin Tian, Qualcomm