May 2018
EunsungPark, LG Electronics
Slide1
OOK Waveform Generation for FDMA Transmission
Date:2018-05-07
Authors:
Introduction
We have agreed to allow FDMA transmission in wide bandwidths such as 40MHz and 80MHz as depicted in [1]Each 20MHz bandwidth only contains one 4MHz sub-band for WUROne wake-up receiver can stay in one of the sub-bands in wide bandwidthIn this contribution, we deal with OOK waveform generation for the WUR FDMA transmission
Eunsung Park, LG Electronics
Slide2
May 2018
OOK Waveform Generation (1/4)
To generate OOK waveform, we consider the followingEach4MHz sub-bandis locatedat the center of 20MHz bandwidth to reduceinterference with each otherThe conventional Wi-Fi transmitter is reusedFor each sub-band, subcarriers from -6to6in each 20MHz bandwidth with the subcarrier spacing of312.5KHz are used7lengthsequence or 13 length sequenceisapplied to each sub-band for the ‘ON’part128- and 256-point IFFTs are performed in 40MHz and 80MHz, respectivelyData rate in each sub-band can be different
Eunsung Park, LG Electronics
Slide3
May 2018
OOK WaveformGeneration(2/4)
For example, consider the following case40MHz bandwidth is used for the FDMA transmissionData rate for STA 1 assigned to sub-band 1 is lowData rate for STA 2 assigned to sub-band 2 is highIn the figure below, WUR-Sync 1, WUR-Sync 2 and WUR-Data 2 are composed of 2us ‘ON’ and ‘OFF’ parts while WUR-Data 1 consists of 4us ‘ON’ and ‘OFF’ partsIn Region A, both sub-bands are based on the 2us signalIn Region B, although sub-band 1 consists of 4us ‘ON’ and ‘OFF’ parts, we can consider both sub-bands are based on the 2us signal to easily generate the FDMA OOK waveform
Eunsung Park, LG Electronics
Slide4
May 2018
Legacy preamble
Mark
WUR-Sync 1
WUR-Data 1
Legacy preamble
Mark
WUR-Sync 2
WUR-Data 2
Sub-band 1
Sub-band 2
Region A
Region B
OOK WaveformGeneration(3/4)
Assume, in Region B, Sub-band 1 and Sub-band 2 have data as shown belowWe can generate OOK waveform every 2us by applying 7 length sequence to every other subcarrier in all sub-bands corresponding to the ‘ON’ partFor the second and sixth 2us waveforms (2~4us, 10~12us), 7 length sequence is applied only to sub-band 2For thethirdandseventh2us waveforms(4~6us,12~14us), 7length sequence isapplied to bothsub-band1 andsub-band2For theforth and eighth2us waveforms(6~8us,14~16us),7length sequence is appliedonly to sub-band 1Then,Perform128-pointIFFT and choose either the first or second 1.6us signal in a 3.2us signal with 1.6us periodicityFinally, prepend0.4usGIIn Region A, the same approach can be employed
Eunsung Park, LG Electronics
Slide5
May 2018
Sub-band 1
Sub-band 2
Information 1
Information 1010
2us 4us 6us 8us 10us 12us 14us 16us
OOK WaveformGeneration(4/4)
For the case where all of the data rates arehigh inall sub-bands, we can use the 2us waveform generation approach as in the previous slideForthe case where all of the data rates are low in all sub-bands,we can also use the same approach or alternatively apply the following approachIn Region A, the approach based on 2us waveform generation as in the previous slide can be appliedIn Region B, although we can employ the 2us waveform generation approach, we can use the following approach based on 4us waveform generationsince both sub-bands are based on 4us signalTo generate each4usOOK waveform,13length sequence is applied toall sub-bands corresponding to the‘ON’partThen, Perform 128-pointIFFT and finallyprepend0.8us GIFor the unification and simple implementation, we prefer to employ the 2us waveform generation based approach in all cases for the FDMA transmission
Eunsung Park, LG Electronics
Slide6
May 2018
Legacy preamble
Mark
WUR-Sync 1
WUR-Data 1
Legacy preamble
Mark
WUR-Sync 2
Sub-band 1
Sub-band 2
Region A
Region B
WUR-Data 2
Proposal
For the WUR FDMA transmission, center 13 subcarriers ineach 20MHzwiththe subcarrier spacing of 312.5KHzare used for sub-bandThe waveform of the WUR portion is generated every2us except for theWUR-Data fieldwith allassigned sub-bands usinglow data rateTo generate each 2us OOK waveform7length sequence is applied to every othersubcarrier in all sub-bands corresponding to the ‘ON’ partPerform128-pointIFFT and 256-point IFFT for 40MHz and 80MHz, respectivelyChooseeither the first or second 1.6us signal in a 3.2us signal with 1.6usperiodicity and finallyprepend 0.4usGIFor the WUR-Data fieldwith allassigned sub-bandsusing low datarate, the waveform is generated every 2us or 4usTo generate each4usOOKwaveform13 length sequence is applied to all sub-bands corresponding to the ‘ON’ partPerform128-point IFFT and 256-point IFFT for 40MHz and 80MHz,respectively, and finallyprepend0.8usGI
Eunsung Park, LG Electronics
Slide7
May 2018
Straw Poll#1
Which option do you prefer for the data rates in the WUR FDMA transmission?Option 1 : allsub-bandsused for WUR PPDU transmission use the same data rateOption 2 : each sub-band can use a different data rateOP1/OP2/A : 0/7/7
Eunsung Park, LG Electronics
Slide8
May 2018
Straw Poll #2
Do you agree to add the following to theTGbaspec?For theWUR FDMA transmission, center 13 subcarriers ineach 20MHz bandwidth with the subcarrier spacing of 312.5KHzcan beusedfor sub-bandFor 40MHz, subcarriers with indices from -38 to -26 and indices from 26 to 38 is used for sub-band 1 and sub-band 2, respectivelyFor80MHz, subcarriers with indices from -102 to -90,indices from-38 to -26,indices from26 to 38 andindices from 90to 102 isused for sub-band1, sub-band 2, sub-band 3 andsub-band4, respectivelyY/N/A :
Eunsung Park, LG Electronics
Slide9
May 2018
Straw Poll #3
Do you agreethe following?Forthe WUR FDMA transmission, the 4us On symbol for WUR LDR can be constructed by two concatenated 2us On symbols used for WUR HDRY/N/A :8/6/9
Eunsung Park, LG Electronics
Slide10
May 2018
Straw Poll #4
Do you agree to add the following to theTGbaspec?FortheWUR-Data field where LDRis applied to all sub-bandsusedfora WURPPDU transmission,thewaveformis generatedevery2us or 4usY/N/A :
Eunsung Park, LG Electronics
Slide11
May 2018
Straw Poll #5
Do you agree to add the following to theTGbaspec?For theWUR FDMA transmission, the following approach can be applied togenerate each 2us OOK waveform7 length sequenceisapplied to every othersubcarrierinall sub-bands corresponding to the ‘ON’ partPerform 128-point IFFT and 256-point IFFT for 40MHz and 80MHz, respectivelyChoose either the first or second 1.6us signal in a 3.2us signal with 1.6us periodicity and finally prepend 0.4us GI
Eunsung Park, LG Electronics
Slide12
May 2018
Straw Poll #6
Do you agree to add the following to theTGbaspec?For the WUR FDMA transmission, the following approach can be applied togenerate each 4us OOK waveform for WUR-Data field where LDR is applied to all sub-bands used for WUR PPDU transmission13 length sequence is applied to all sub-bands corresponding to the ‘ON’ partPerform128-point IFFT and 256-point IFFT for 40MHz and 80MHz,respectively,and finally prepend 0.8us GI
Eunsung Park, LG Electronics
Slide13
May 2018
References
[1] IEEE802.11-17/1625r6Efficient FDMA MU Transmission Schemes for WUR WLAN
Eunsung Park, LG Electronics
Slide14
May 2018
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