1. Extra tones in the preamble
November, 2015
Extra tones in the preamble
Date:
Authors:
Name
Affiliation
Address
Phone
Robert Stacey
Intel
2111 NE 25th Ave, Hillsboro OR 97124, USA     
Shahrnaz Azizi
Po-Kai Huang
Qinghua Li
Xiaogang Chen
Chitto Ghosh
Laurent Cariou
Yaron Alpert
Assaf Gurevitz
Ilan Sutskover
Intel, Marvell, et. al.

2. Authors (continued) Hongyuan Zhang Marvell
Name
Affiliation
Address
Phone
Hongyuan Zhang
Marvell
5488 Marvell Lane, Santa Clara, CA, 95054
Yakun Sun
Lei Wang
Liwen Chu
Jinjing Jiang
Yan Zhang
Rui Cao
Sudhir Srinivasa
Bo Yu
Saga Tamhane
Mao Yu
Xiayu Zheng
Christian Berger
Niranjan Grandhe
Hui-Ling Lou

3. Authors (continued) Alice Chen Albert Van Zelst Alfred Asterjadhi
Name
Affiliation
Address
Phone
Alice Chen
Qualcomm
5775 Morehouse Dr. San Diego, CA, USA
Albert Van Zelst
Straatweg 66-S Breukelen, 3621 BR Netherlands
Alfred Asterjadhi
Arjun Bharadwaj
Bin Tian
Carlos Aldana
1700 Technology Drive San Jose, CA 95110, USA
George Cherian
Gwendolyn Barriac
Hemanth Sampath
Lin Yang
Menzo Wentink
Naveen Kakani
2100 Lakeside Boulevard Suite 475, Richardson TX 75082, USA
Raja Banerjea
1060 Rincon Circle San Jose CA 95131, USA
Richard Van Nee

4. Authors (continued) Rolf De Vegt Qualcomm Sameer Vermani Simone Merlin
Name
Affiliation
Address
Phone
Rolf De Vegt
Qualcomm
1700 Technology Drive San Jose, CA 95110, USA
Sameer Vermani
5775 Morehouse Dr. San Diego, CA, USA
Simone Merlin
Tao Tian
Tevfik Yucek  
VK Jones
Youhan Kim
Ron Porat
Broadcom
Sriram Venkateswaran
Matthew Fischer
Leo Montreuil
Andrew Blanksby
Vinko Erceg

5. Authors (continued) James Yee Mediatek
Name
Affiliation
Address
Phone
James Yee
Mediatek
No. 1 Dusing 1st Road, Hsinchu, Taiwan  
Alan Jauh
Chingwa Hu
Frank Hsu
Thomas Pare
USA
2860 Junction Ave, San Jose, CA 95134, USA
ChaoChun Wang
James Wang
Jianhan Liu
Tianyu Wu
Zhou Lan
Russell Huang
Joonsuk Kim
Apple
Aon Mujtaba  
Guoqing Li
Eric Wong
Chris Hartman

6. Authors (continued) Peter Loc Le Liu Jun Luo Yi Luo Huawei Yingpei Lin
Name
Affiliation
Address
Phone
Peter Loc
Huawei
Le Liu
F1-17, Huawei Base, Bantian, Shenzhen
Jun Luo
5B-N8, No.2222 Xinjinqiao Road, Pudong, Shanghai
Yi Luo
Yingpei Lin
Jiyong Pang
Zhigang Rong
10180 Telesis Court, Suite 365, San Diego, CA  NA
Rob Sun
303 Terry Fox, Suite 400 Kanata, Ottawa, Canada
David X. Yang
Yunsong Yang
Junghoon Suh
Jiayin Zhang
Edward Au
Teyan Chen
Yunbo Li

7. Authors (continued) Jinmin Kim LG Electronics
Name
Affiliation
Address
Phone
Jinmin Kim
LG Electronics
19, Yangjae-daero 11gil, Seocho-gu, Seoul , Korea
Kiseon Ryu
Jinyoung Chun
Jinsoo Choi
Jeongki Kim
Dongguk Lim
Suhwook Kim
Eunsung Park
JayH Park
HanGyu Cho
Thomas Derham
Orange
Bo Sun
ZTE
#9 Wuxingduan, Xifeng Rd., Xi'an, China
Kaiying Lv
Yonggang Fang
Ke Yao
Weimin Xing
Brian Hart
Cisco Systems
170 W Tasman Dr, San Jose, CA 95134
Pooya Monajemi

8. Authors (continued) Fei Tong Hyunjeong Kang Samsung Kaushik Josiam
Name
Affiliation
Address
Phone
Fei Tong
Samsung
Innovation Park, Cambridge CB4 0DS (U.K.)
Hyunjeong Kang
Maetan 3-dong; Yongtong-Gu Suwon; South Korea
Kaushik Josiam
1301, E. Lookout Dr, Richardson TX 75070
(972)
Mark Rison
Rakesh Taori
(972)
Sanghyun Chang
Yasushi Takatori
NTT
1-1 Hikari-no-oka, Yokosuka, Kanagawa Japan
Yasuhiko Inoue
Shoko Shinohara
Yusuke Asai
Koichi Ishihara
Junichi Iwatani
Akira Yamada
NTT DOCOMO
3-6, Hikarinooka, Yokosuka-shi, Kanagawa, , Japan
Fujio Watanabe
3240 Hillview Ave, Palo Alto, CA 94304
Haralabos Papadopoulos

9. Authors (continued) Name Affiliation Address Phone Email Masahito Mori
Sony Corp.
Yusuke Tanaka
Yuichi Morioka
Kazuyuki Sakoda
William Carney

10. November, 2015
Outline
To increase data subcarriers in SIG-A/SIG-B, we propose to allocate 4 extra subcarriers to 1x portion of the HE preamble not including L-STF and L-LTF fields.
With extra tones, there are some power imbalance issues need to be discussed.
Intel, Marvell, et. al.

11. Motivation for extra subcarriers in the HE preamble
November, 2015
Motivation for extra subcarriers in the HE preamble
Due to the limitation that L-LTF covers only 52 subcarriers, HE-SIG-A/HE-SIG-B can only transmit information on 48 subcarriers.
More payloads were added in HE-SIG-A for 11ax
HE-SIG-B may need to convey large amount of information depending on the number of scheduled STAs
Propose to add training subcarriers in L-SIG
This extension provides extra channel estimates for the subsequent symbols (HE-SIGA/HE-SIGB)
Symbols that follow L-SIG will have a subcarrier allocation similar to 11n/ac
Intel, Marvell, et. al.

12. Increased Subcarrier Allocation in L-SIG
November, 2015
Increased Subcarrier Allocation in L-SIG
Allocate additional subcarriers in L-SIG
They are extended L-LTF subcarriers used for channel estimation;
Allows more data bits in HE-SIG-A and HE-SIG-B than that of the L-SIG
The repeated extra subcarriers in RL-SIG allow comparable SNR performance as L-LTF
Intel, Marvell, et. al.

13. Impacts to legacy/11ax devices
November, 2015
Impacts to legacy/11ax devices
For legacy devices:
The extension would not impact the performance of legacy devices in decoding L-SIG;
The extended subcarriers are simply disregarded by the legacy devices.
For 11ax devices:
Aware of the additional subcarriers and use them for channel estimation;
Decoding L-SIG similar to legacy devices.
Intel, Marvell, et. al.

14. November, 2015
Power Adjustment
We propose to transmit L-SIG, RL-SIG, HE-SIG-A and HE-SIG-B with the same total power as L-LTF field
We could scale the power on L-SIG and RL-SIG to maintain the same power per tone as in L-LTF. But keeping the same power per OFDM symbol is more straightforward.
By keeping the same power per symbol in L-SIG/RL-SIG and L-LTF, the estimated channel on L-LTF and those obtained from extra subcarriers of L-SIG/RL-SIG have slightly power imbalance.
Friendly to amplitude immunity modulation (BPSK/QPSK);
If 16QAM/64QAM is applied in SIGB, receiver may choose to de-boost the CE with factor sqrt(52/56) on the tones spanned by L-LTF.
Intel, Marvell, et. al.

15. November, 2015
Summary
To increase HE-SIG-A/HE-SIG-B payload, propose to add 4 extra subcarriers on L-SIG and RL-SIG for additional LTF training.
Add 4 extra tones starting from L-SIG, through R-LSIG, HE-SIG-A and HE-SIG-B fields.
Propose to transmit L-SIG, RL-SIG, HE-SIG-A and HE-SIG-B with the same total power as L-LTF field.
Receiver adjusts the power of estimated channel accordingly if higher modulation order (>QPSK) is used on HE-SIG-B.
Intel, Marvell, et. al.

16. Straw poll Do you support to:
November, 2015
Straw poll
Do you support to:
Allocate 4 extra subcarriers, two at each edge of each 20MHz sub-channel, for L-SIG, RL-SIG, HE-SIG-A and HE-SIG-B fields in 11ax PPDUs.
The 4 subcarriers added to the L-SIG and RL-SIG fields are transmitted with known TBD BPSK constellations (+-1).
The number of data subcarriers in HE-SIG-A and HE-SIG-B fields are increased by 4 in each 20MHz sub-channel.
L-SIG, RL-SIG, HE-SIG-A and HE-SIG-B fields are always transmitted with the same total power as L-LTF field (in cases when L-LTF is not being boosted).
Intel, Marvell, et. al.