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TGn Sync Complete Proposal

TGn Sync Complete Proposal. Aon Mujtaba, Agere Systems Inc., ( mujtaba@agere.com ) Adrian P Stephens, Intel Corporation, ( adrian.p.stephens@intel.com ) Alek Purkovic, Nortel Networks ( apurkovi@nortelnetworks.com ) Andrew Myles, Cisco Systems ( amyles@cisco.com )

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TGn Sync Complete Proposal

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  1. TGn Sync Complete Proposal Aon Mujtaba, Agere Systems Inc., (mujtaba@agere.com) Adrian P Stephens, Intel Corporation, (adrian.p.stephens@intel.com) Alek Purkovic, Nortel Networks (apurkovi@nortelnetworks.com) Andrew Myles, Cisco Systems (amyles@cisco.com) Brian Johnson, Nortel Networks Corporation, (brjohnso@nortelnetworks.com) Chiu Ngo, Samsung Electronics Co. Ltd., (chiu.ngo@samsung.com) Daisuke Takeda, Toshiba Corporation, (daisuke.takeda@toshiba.co.jp) Darren McNamara, Toshiba Corporation, (Darren.McNamara@toshiba-trel.com) Dongjun (DJ) Lee, Samsung Electronics Co. Ltd., (djthekid.lee@samsung.com) David Bagby, Calypso Consulting, (david.bagby@ieee.org) Eldad Perahia, Cisco Systems, (eperahia@cisco.com) Hiroshi Oguma, Tohoku University, (oguma@wit.riec.tohoku.ac.jp) Hiroyuki Nakase, Tohoku University, (nakase@riec.tohoku.ac.jp) Huanchun Ye, Atheros Communications Inc., (hcye@atheros.com) Hui-Ling Lou, Marvell Semiconductor Inc., (hlou@marvell.com) Isaac Lim Wei Lih, Panasonic (wllim@psl.com.sg) James Chen, Marvell Semiconductor Inc., (jamesc@marvell.com) Syed Aon Mujtaba, Agere Systems, et. al.

  2. Authors (continued) James Mike Wilson, Intel Corporation, (james.mike.wilson@intel.com) Jan Boer, Agere Systems Inc., (janboer@agere.com) Jari Jokela, Nokia, (jari.jokela@nokia.com) Jeff Gilbert, Atheros Communications Inc., (gilbertj@atheros.com) Job Oostveen, Royal Philips Electronics, (job.oostveen@philips.com) Joe Pitarresi, Intel Corporation, (joe.pitarresi@intel.com) Jörg Habetha, Royal Philips Electronics, (joerg.habetha@philips.com) John Sadowsky, Intel Corporation, (john.sadowsky@intel.com) Jon Rosdahl, Samsung Electronics Co. Ltd., (jon.rosdahl@partner.samsung.com) Kiyotaka Kobayashi, Panasonic (kobayashi.kiyotaka@jp.panasonic.com) Li Yuan, Institute for Infocomm Research, (liyuan@i2r.a-star.edu.sg) Luke Qian, Cisco Systems, (lchia@cisco.com) Mary Cramer, Agere Systems (mecramer@agere.com) Masahiro Takagi, Toshiba Corporation, (masahiro3.takagi@toshiba.co.jp) Monisha Ghosh, Royal Philips Electronics, (monisha.ghosh@philips.com) Nico van Waes, Nokia, (nico.vanwaes@nokia.com) Osama Aboul-Magd, Nortel Networks Corporation, (osama@nortelnetworks.com) Paul Feinberg, Sony Electronics Inc., (paul.feinberg@am.sony.com) Pen Li , Royal Philips Electronics (pen.li@philips.com) Syed Aon Mujtaba, Agere Systems, et. al.

  3. Authors (continued) Peter Loc, Marvell Semiconductor Inc., (ploc@marvell.com) Pieter-Paul Giesberts, Agere Systems Inc., (pgiesberts@agere.com) Richard van Leeuwen, Agere Systems Inc., (rleeuwen@agere.com) Ronald Rietman, Royal Philips Electronics, (ronald.rietman@philips.com) Seigo Nakao, SANYO Electric Co. Ltd., (snakao@gf.hm.rd.sanyo.co.jp) Sheung Li, Atheros Communications Inc., (sheung@atheros.com) Stephen Shellhammer, Intel, (stephen.j.shellhammer@intel.com) Sumei Sun, Institute for Infocomm Research, (sunsm@i2r.a-star.edu.sg) Taekon Kim, Samsung Electronics Co. Ltd., (taekon.kim@samsung.com) Takashi Fukagawa, Panasonic, (fukagawa.takashi@jp.panasonic.com) Takushi Kunihiro, Sony Corporation, (kuni@wcs.sony.co.jp) Teik-Kheong (TK) Tan, Royal Philips Electronics, (tktan@philips.com) Tomoko Adachi, Toshiba Corporation, (tomo.adachi@toshiba.co.jp) Tomoya Yamaura, Sony Corporation, (yamaura@wcs.sony.co.jp) Tsuguhide Aoki, Toshiba Corporation, (tsuguhide.aoki@toshiba.co.jp) Victor Stolpman, Nokia, (victor.stolpman@nokia.com) Won-Joon Choi, Atheros Communications Inc., (wjchoi@atheros.com) Xiaowen Wang, Agere Systems Inc., (xiaowenw@agere.com) Syed Aon Mujtaba, Agere Systems, et. al.

  4. Authors (continued) Yasuhiko Tanabe, Toshiba Corporation, (yasuhiko.tanabe@toshiba.co.jp) Yasuhiro Tanaka, SANYO Electric Co. Ltd., (y_tanaka@gf.hm.rd.sanyo.co.jp) Yoshiharu Doi, SANYO Electric Co. Ltd., (doi@gf.hm.rd.sanyo.co.jp) Youngsoo Kim, Samsung Electronics Co. Ltd., (KimYoungsoo@samsung.com) Yuichi Morioka, Sony Corporation, (morioka@wcs.sony.co.jp) Syed Aon Mujtaba, Agere Systems, et. al.

  5. TGn Sync Mission Statement • Develop a scalable architecture to support present and emerging applications • Foster a broad industry representation across market segments Syed Aon Mujtaba, Agere Systems, et. al.

  6. Broad Industry Representation PC • OEM / System Vendors • Cisco • Nokia • Nortel • Panasonic • Samsung • Sanyo • Sony • Toshiba • Semi Vendors • Agere • Atheros • Intel • Marvell • Philips Enterprise Consumer Electronics Asia Pacific / Europe / North America Public Access Handset Semiconductor Syed Aon Mujtaba, Agere Systems, et. al.

  7. Scalable Architecture across several dimensions Market segments PC Enterprise Consumer Electronics Public Access Handset 140 / 243Mbps 315Mbps 630Mbps 10MHz (.11j/p) Performance over time 20MHz Regulatory Domains 40MHz Syed Aon Mujtaba, Agere Systems, et. al.

  8. Mandatory Features: • Two antennas • 20 / 40MHz • 140 / 243 Mbps … And a well-defined Core Syed Aon Mujtaba, Agere Systems, et. al.

  9. PHY Summary of TGn Sync Proposal • Mandatory Features: • 1 or 2 Spatial Streams • 20MHz and 40MHz* channelization • 1/2, 2/3, 3/4, and 7/8 channel coding rates • 400ns & 800ns Guard Interval • Full & seamless interoperability with a/b/g • Optional Features: • Transmit Beamforming • Low Density Parity Check (LDPC) Coding • 3 or 4 spatial streams 140Mbps in 20MHz 243Mbps in 40MHz *Not required in regulatory domains where prohibited. Syed Aon Mujtaba, Agere Systems, et. al.

  10. MAC Summary of TGn Sync Proposal • Mandatory Features: • MAC level frame aggregation • RX assisted link adaptation • QoS support (802.11e) • MAC header compression • Block ACK compression • Legacy compatible protection • 20/40 MHz channel management • Optional Features: • Bi-directional data flow • MIMO RX Power management Syed Aon Mujtaba, Agere Systems, et. al.

  11. PHY Syed Aon Mujtaba, Agere Systems, et. al.

  12. PHY Architectural Features • Mandatory features: • Spatial division multiplexing (SDM) of 2 Spatial Streams • Interoperable 20MHz and 40MHz channelizations • Channel Coding Rates: 1/2, 2/3, 3/4, and 7/8 • Guard Interval: 400ns and 800ns • Optional robustness & throughput enhancement: • Transmit beamforming • Advanced coding (LDPC) • SDM with 3 or 4 spatial streams Max Mandatory rate in 20MHz = 140 Mbps Max Mandatory rate in 40MHz = 243 Mbps (with 2x2 architecture using 2 spatial streams) with the option to scale to 630Mbps Syed Aon Mujtaba, Agere Systems, et. al.

  13. Modifications to PHY Arch after Berlin • Removed Options • Reed Solomon coding • Changed to mandatory in 20MHz: • 7/8 code rate • 400ns (in addition to 800ns GI) • Highest Rate = 140Mbps in 20MHz 243Mbps in 40MHz Syed Aon Mujtaba, Agere Systems, et. al.

  14. Scalable PHY Architecture Mandatory Optional Robustness Enhancement Closed Loop TX BF Open Loop SDM Robustness Enhancement LDPC Conv. Coding Rate Feedback Throughput Enhancement 2 Spatial Streams 4 Spatial Streams Regulatory Constraints Low Cost & Robust 20 MHz 40 MHz  140 Mbps 630 Mbps 243 Mbps Syed Aon Mujtaba, Agere Systems, et. al.

  15. Mapping Spatial Streams to Multiple Antennas • Number of spatial streams = Number of TX antennas • 1 spatial stream mapped to 1 antenna • Spatial division multiplexing • Equal rates on all spatial streams • Number of spatial streams ≤ Number of TX antennas • Each spatial stream mapped to all transmit antennas • Optional transmit beamforming • Optimal technique for realizing array and diversity gains • Requires channel state info at the TX • Supports unequal rates on different spatial streams • Optional orthogonal spatial spreading • Exploits all transmit antennas • No channel state info at TX required • No change at RX is needed due to per spatial stream training Syed Aon Mujtaba, Agere Systems, et. al.

  16. Mandatory PHY Features Syed Aon Mujtaba, Agere Systems, et. al.

  17. TX Arch: Spatial Division Multiplexinge.g.2 Spatial streams with 2 TX antennas iFFT Modulator Preamble insert GI window symbols Pilots Frequency Interleaver Constellation Mapper Scrambled MPDU iFFT Modulator Preamble Channel Encoder Puncturer Spatial parser insert GI window symbols Pilots Frequency Interleaver Constellation Mapper Syed Aon Mujtaba, Agere Systems, et. al.

  18. Tone Design for 20 and 40 MHz • 20 MHz: • Identical to 802.11a • 64 point FFT • 48 data tones • 4 pilot tones -26 -21 -7 -1 +1 +7 +21 +26 Tone Fill in the Guard Band • 40 MHz: • 128 point FFT • 108 data tones • 6 pilot tones -25 -11 +11 +25 +53 -53 +32 -2 +2 -64 -58 -32 -6 +6 +58 +63 Legacy 20 MHz in Lower Sub-Channel Legacy 20 MHz in Upper Sub-Channel Syed Aon Mujtaba, Agere Systems, et. al.

  19. Scalable Basic MCS Set Mandatory MCS ‡ Duplicate format, BPSK R = ½ provides 6 Mbps for 40 MHz channels ½ GI applies to all data rates in 20MHz Optional MCS Syed Aon Mujtaba, Agere Systems, et. al.

  20. HT-PPDU Format in 20MHz HT STF HT LTF-1 HT LTF-2 L-STF L-LTF L-SIG HT-SIG HT-DATA ANT_1 20MHz L-STF L-LTF L-SIG HT-SIG HT-DATA ANT_2 20MHz Legacy Compatible Preamble HT-specific Preamble Legend L- Legacy HT- High Throughput STF Short Training Field LTF Long Training Field SIG Signal Field Legacy Compatible Can be decoded by anylegacy 802.11a or g compliant device for interoperability Syed Aon Mujtaba, Agere Systems, et. al.

  21. L-STF L-LTF L-SIG HT-SIG HT-DATA Duplicate L-STF Duplicate L-LTF Dup. L-SIG Duplicate HT-SIG HT-PPDU Format in 40MHz ANT_1 40MHz HT STF HT LTF-1 HT LTF-2 L-STF L-LTF L-SIG HT-SIG HT-DATA ANT_2 40MHz Duplicate L-STF Duplicate L-LTF Dup. L-SIG Duplicate HT-SIG Legacy Compatible Preamble HT-specific Preamble Syed Aon Mujtaba, Agere Systems, et. al.

  22. Spoofing • Spoofing is the use of the legacy RATE and LENGTH fields to keep the legacy STA off the air for a desired period of time • The duration indicated in the L-SIG can exceed the actual duration in the HT-SIG  MAC uses this as a protection mechanism • For a HT-PPDU, L-SIG RATE is hard-coded at 6 Mbps • max MSDU length = 2304 Bytes spoofing duration up to ~3 msec Syed Aon Mujtaba, Agere Systems, et. al.

  23. HT PPDU Detection L-STF L-LTF L-SIG HT-SIG • Auto-detection scheme on HT-SIG • Q-BPSK modulation (BPSK w/ 90-deg rotation) • Invert the polarity of the pilot tones • Combined methods provide speed and reliability • Reserved bit in the L-SIG can not be used • Vendors were not given guidance from the 802.11a/g standard to set the reserved bit to a specific value or Legacy DATA L-STF L-LTF L-SIG Legacy Compatible Preamble Syed Aon Mujtaba, Agere Systems, et. al.

  24. MIMO AGC single spatial stream multiple spatial streams L-STF L-LTF L-SIG HT-SIG HT-DATA • Tone interleaving the L-STF leads to perfect decorrelation • if L-STF is tone-interleaved, it will hurt legacy interoperability with cross-correlation RX • Cyclic delay across the L-STF is nearly decorrelated • however, large cyclic delay hurts interoperability with cross-correlation RX • and, small cyclic delay suffers from inaccurate power estimation, as shown next power measurement AGC locked Accurate measurement of MIMO channel power requires uncorrelated STFs Syed Aon Mujtaba, Agere Systems, et. al.

  25. Power Fluctuation of L-STF w.r.t Data Data power Power fluctuation with tone interleaving is within 1dB of the data power 1 0.9 STF = Tone Interleaved STF = Cyclic Delay 0.8 2x2, TGn Channel D SNR = 30dB 0.7 0.6 CDF(x) 0.5 Introduce a dedicated STF for MIMO that is tone interleaved Reduces 1 bit in the ADC  cost & power savings 0.4 0.3 0.2 0.1 0 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 x = Power fluctuation of AGC setting w.r.t. data power (dB) Syed Aon Mujtaba, Agere Systems, et. al.

  26. Power Fluctuation of HT-LTF w.r.t. Data Data power 1 0.9 Large deviation of HT-LTF power wrt data power will result in higher channel estimation error HT-LTF = Tone Interleaved 0.8 HT-LTF = Walsh + Cyclic Delay 0.7 2x2, TGn Channel D SNR = 30dB 0.6 CDF(x) 0.5 0.4 0.3 HT-LTF should be tone interleaved 0.2 0.1 0 -10 -8 -6 -4 -2 0 2 4 x = Power fluctuation of HT-LTF w.r.t. data (dB) Syed Aon Mujtaba, Agere Systems, et. al.

  27. Tone Interleaved HT Training Fields • HT-STF • 2nd AGC measurement is used to fine-tune MIMO reception • HT-LTF • Used for MIMO channel estimation • Additional frequency or time alignment Syed Aon Mujtaba, Agere Systems, et. al.

  28. Summary of HT-LTF • Robust design • Tone interleaving reduces power fluctuation • 2 symbols per field • 3dB of channel estimation gain with baseline per-tone estimation • Enables additional frequency offset estimation • Per spatial stream training • HT-LTF and HT-Data undergo same spatial transformation • Number of HT-LTFs = Number of spatial streams Syed Aon Mujtaba, Agere Systems, et. al.

  29. Is 40MHz Mandatory? • Both 20 MHz & 40 MHz capabilities are mandatory • With exceptions due to regulatory requirements • Capability depends on regulatory domain (just like channelization plans): • 20/40 MHz capable devices • 20 MHz only capable devices • Both types of devices are fully interoperable Syed Aon Mujtaba, Agere Systems, et. al.

  30. 20/40 MHz Operation Where Used Where Bought Syed Aon Mujtaba, Agere Systems, et. al.

  31. 2x2-40 MHz 4x4-20 MHz 2x3-20 MHz w/ short GI 2x2-20 MHz w/ short GI Why 40MHz is Mandatory? • 2x2 – 40 MHz • Only 2 RF chains => Cost effective & low power • Lower SNR at same throughput => Enhanced robustness 260 240 220 200 Sweet spot for 100Mbps top-of-MAC 180 160 140 Over the Air Throughput (Mbps) 120 100 80 Basic MIMO MCS set No impairments 1000 byte packets TGn channel model B 60 40 20 0 0 5 10 15 20 25 30 35 SNR (dB) Syed Aon Mujtaba, Agere Systems, et. al.

  32. 20/40 MHz Interoperability • 40 MHz PPDU into a 40 MHz receiver • Get 3dB processing gain – duplicate format allows combining the legacy compatible preamble and the HT-SIG in an MRC fashion • 20 MHz PPDU into a 40 MHz receiver • The active 20 MHz sub-channel is detected using energy measurement of the two sub-channels • Inactive tones at the FFT output (i.e. 64 out of 128) are not used • 40 MHz PPDU into a20 MHz receiver • One 20 MHz sub-channel is sufficient to decode the L-SIG and the HT-SIG • 20 MHz RX (either HT or legacy) will defer properly to 40 MHz PPDU • See MAC slides for additional information on 20/40 inter-op Syed Aon Mujtaba, Agere Systems, et. al.

  33. Optional PHY Features Syed Aon Mujtaba, Agere Systems, et. al.

  34. Seamless Arch Extension for TX BFe.g. 2 Spatial Streams across 3 Transmit Antennas Per Spatial Stream Processing: HT-LTF & HT-Data undergo same spatial transformation HT LTF iFFT Mod. insert GI window Pilots Frequency Interleaver Constellation Mapper iFFT Mod. insert GI Spatial Steering Matrix window HT LTF Scrambled MPDU Channel Encoder Puncturer Spatial Parser Pilots iFFT Mod. insert GI Frequency Interleaver Constellation Mapper window Syed Aon Mujtaba, Agere Systems, et. al.

  35. Why introduce TX Beamforming? 1000 byte packets No impairment 20MHz, channel D 4 TX-antenna AP  2 RX-antenna client ~10 dB gain of 4x2-ABF over 2x2-SDM => cost effective client Syed Aon Mujtaba, Agere Systems, et. al.

  36. Optional LDPC • Capacity approaching FEC • Iterative decoding  superior performance • Strong performance in AWGN and fading channels • Typically 2-4 dB improvement over convolutional codes, depending on channel conditions • Code structure enables low complexity architectures • Layered belief propagation reduces memory requirements and improves convergence performance Syed Aon Mujtaba, Agere Systems, et. al.

  37. Benefit of LDPC Coding 4 dB of coding gain Syed Aon Mujtaba, Agere Systems, et. al.

  38. PHY Summary • Mandatory Rate of 140Mbps in 20MHz: • 2 Spatial Streams • 7/8th rate coding • 400ns Guard Interval • Low Cost & Robust Throughput Enhancement: • Scalable to 243 Mbps in 40MHz • Optional Robustness/Throughput Enhancements: • LDPC Coding • Transmit Beamforming • Scalable to 630Mbps with 4 spatial streams in 40MHz Syed Aon Mujtaba, Agere Systems, et. al.

  39. MAC Syed Aon Mujtaba, Agere Systems, et. al.

  40. Scalable MAC Architecture • LEGACY INTEROP. • Long NAV • Pairwise Spoofing • Single-Ended Spoofing Robust & Scalable MAC Architecture • ADDITIONAL EFFICIENCY • Header Compression • Multi-Receiver Aggregation • Bi-Directional Data Flow • BA Enhancements • BASELINE MAC • Robust Aggregation • QoS Support (802.11e) • Rx assisted link adapt. • CHANNEL MANAGEMENT • 20/40 MHz Modes Syed Aon Mujtaba, Agere Systems, et. al.

  41. Modifications to MAC Arch • Removed • TSPEC negotiation • Packet loss priority • Added • Enhanced Block ACK Syed Aon Mujtaba, Agere Systems, et. al.

  42. Baseline MAC Features Syed Aon Mujtaba, Agere Systems, et. al.

  43. Robust Structure Aggregation is a purely-MAC function PHY has no knowledge of MPDU boundaries Simplest MAC-PHY interface Control and data MPDUs can be aggregated Aggregation Structure Syed Aon Mujtaba, Agere Systems, et. al.

  44. Aggregate Exchange Sequences • Aggregate exchange sequences include single frames or groups of frames that are exchanged “at the same time” • Allows effective use of Aggregate Feature • Allows control and data to be sent in the same PPDU • An initiator sends a PPDU and a responder may transmit a response PPDU • Either PPDU can be an aggregate (“Initiator” / “responder” are new terms relating to roles in aggregate exchange protocol) Syed Aon Mujtaba, Agere Systems, et. al.

  45. Basic Aggregate Exchange Syed Aon Mujtaba, Agere Systems, et. al.

  46. RX Assisted Link Adaptation Protocol • Support for PHY closed-loop modes with on-the-air signalling • Request for training and feedback are carried in control frames • Rate feedback supported • Transmit beamforming training supported • sounding packet • calibration exchange • Timing of response is not constrained permitting a wide range of implementation options Syed Aon Mujtaba, Agere Systems, et. al.

  47. RX Assisted Link Adaptation Protocol Syed Aon Mujtaba, Agere Systems, et. al.

  48. Features Providing Additional Efficiency Syed Aon Mujtaba, Agere Systems, et. al.

  49. Reverse Direction Data Flow • Gives an opportunity for a responder to transmit data to an initiator during the initiator’s TXOP • Aggregates data with response control MPDUs • Reduces Contention • Effective in increasing TCP/IP performance Syed Aon Mujtaba, Agere Systems, et. al.

  50. Reverse Direction Protocol Syed Aon Mujtaba, Agere Systems, et. al.

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