1. OOK Waveform Generation
Month Year
doc.: IEEE yy/xxxxr0
January 2018
OOK Waveform Generation
Date:
Authors:
Name
Affiliation
Address
Phone
Eunsung Park
LG Electronics
19, Yangjae-daero 11gil, Seocho-gu, Seoul , Korea
Dongguk Lim
Jinyoung Chun
Jinsoo Choi
Eunsung Park, LG Electronics
John Doe, Some Company

2. January 2018
Introduction
Symbol structures for two data rates are defined in the 11ba SFD [1]
4us and 2us ON-Signals are used for low and high data rates, respectively
SFD further needs a detailed description for OOK waveform generation, i.e. 4us/2us ON-Signals generation
This contribution deals with how to generate 4us/2us ON-signals
Eunsung Park, LG Electronics

3. 4us ON-Signal (1/2) SFD says
January 2018
4us ON-Signal (1/2)
SFD says
R.3.3.C: When a single band is used for transmission of WUR PPDU, the OOK waveform of WUR PPDU is generated by using contiguous 13 subcarriers with the subcarrier spacing of kHz:
The center subcarrier is null.
Thus, 4us ON-Signal for the low data rate can be generated by just reusing the conventional OFDM transmitter as follows
Apply 13-length sequence with center coefficient of zero to certain contiguous 13 subcarriers within 20MHz (i.e., 64 subcarriers)
Perform 64-point IFFT and prepend 0.8us GI
Eunsung Park, LG Electronics

4. January 2018
4us ON-Signal (2/2)
As for the 13-length sequence, we recommend the following sequences which are beneficial to PAPR [2]
[1,1,1,-1,-1,-1,0,-1,1,-1,-1,1,-1]
[1,-1,1,-1,-1,1,0,-1,-1,1,1,1,1] * (1+j)/sqrt(2)
PAPRs are shown in Appendix A
With regard to the location of 13 subcarriers for the single band transmission, we can use one of some sub-bands which need to be defined
Some examples of multiple sub-bands in 20MHz were proposed in [3]
Eunsung Park, LG Electronics

5. 2us ON-signal (1/3) January 2018
Some approaches for 2us ON-Signal generation for the data rate of 250Kbps were proposed
Constellation based approach with 13-length sequence [4]
Masking based approach with 13-length sequence [5]
32-point IFFT based approach with 7-length sequence [6]
64-point IFFT based approach with 7-length sequence applied to every other index [7]
We recommend using masking based and 64-point IFFT (or 32-point IFFT) based approaches
Constellation based approach can simply generate the OOK symbol by just reusing the conventional Wi-Fi transmitter but this approach causes energy even in OFF duration
Masking based approach with two sequences in the previous slide has good PAPR and does not cause out of band (OOB) emission issue as shown in Appendix B
64-point IFFT based approach is similar to 32-point IFFT based approach and this approach with the 7-length sequence which has low PAPR has no OOB issue as shown in Appendix C
Eunsung Park, LG Electronics

6. 2us ON-signal (2/3) January 2018
For the masking based approach, the following procedure can be applied to generate the 4us OOK symbol
Apply 13-length sequence to contiguous 13 subcarriers
Perform 64-point IFFT, prepend 0.8us GI and apply masking to each 4us symbol as follows
As for the 13-length sequence, we recommend the following sequences which are beneficial to PAPR and OOB emission as shown in Appendix B
[1,1,1,-1,-1,-1,0,-1,1,-1,-1,1,-1]
[1,-1,1,-1,-1,1,0,-1,-1,1,1,1,1] * (1+j)/sqrt(2)
Note that we can unify the 13-length sequence between 2us and 4us ON-Signal generation, and thus, we just apply masking to the 4us ON-Signal for 2us ON-Signal generation
0us us us 1
0us us us 1
Information ‘0’
Information ‘1’
Eunsung Park, LG Electronics

7. January 2018
2us ON-signal (3/3)
For the 64-point IFFT based approach, the following procedure can be applied to generate the 2us ON-Signal
Apply 7-length sequence to every other subcarrier in contiguous 13 subcarriers, i.e. indices of 1,3,5,7,9,11 and 13 and set the others to zero
The coefficient at the 7th subcarrier is also zero
Perform 64-point IFFT and choose either the first or second 1.6us part in a generated 3.2us signal with 1.6us periodicity
Prepend 0.4us GI
Note that this procedure creates the same signal as in [6] when the same 7-length sequence is applied
As for the 7-length sequence, we recommend the following sequence
[1,-1,1,0,-1,-1,-1]
This sequence has better PAPR and causes less OOB emission compared to the partial STF sequence proposed in [6] as shown in Appendix C
Eunsung Park, LG Electronics

8. January 2018
Conclusion
We have proposed several procedures for 4us and 2us ON-Signals generation which are used for 62.5Kbps and 250Kbps, respectively
For 4us ON-Signal generation, we recommend the following 13-length sequences which have low PAPR
[1,1,1,-1,-1,-1,0,-1,1,-1,-1,1,-1]
[1,-1,1,-1,-1,1,0,-1,-1,1,1,1,1] * (1+j)/sqrt(2)
For 2us ON-Signal generation (or 4us OOK symbol generation for 250Kbps), we recommend the masking based approach with two sequences above
This approach needs just additional masking procedure in 4us ON-Signal generation
In addition, for 2us ON-Signal generation, we also recommend the 64-point IFFT based approach with the following 7-length sequence which is applied to every other subcarrier in 13 subcarriers (or recommend the 32-point IFFT based approach with the following 7-length sequence)
[1,-1,1,0,-1,-1,-1]
Eunsung Park, LG Electronics

9. Straw Poll #1 Do you agree to add the following to the 11ba SFD?
January 2018
Straw Poll #1
Do you agree to add the following to the 11ba SFD?
The following is an example of a 4us ON-Signal generation process for the data rate of 62.5kbps
Apply one of the following 13-length sequences to contiguous 13 subcarriers
[1,1,1,-1,-1,-1,0,-1,1,-1,-1,1,-1]
[1,-1,1,-1,-1,1,0,-1,-1,1,1,1,1] * (1+j)/sqrt(2)
Perform 64-point IFFT and prepend 0.8us GI
Eunsung Park, LG Electronics

10. Straw Poll #2 Do you agree to add the following to the 11ba SFD?
January 2018
Straw Poll #2
Do you agree to add the following to the 11ba SFD?
The following is an example of a 4us OOK symbol generation process for the data rate of 250kbps
Apply one of the following 13-length sequences to contiguous 13 subcarriers
[1,1,1,-1,-1,-1,0,-1,1,-1,-1,1,-1]
[1,-1,1,-1,-1,1,0,-1,-1,1,1,1,1] * (1+j)/sqrt(2)
Perform 64-point IFFT, prepend 0.8us GI and apply masking to each 4us symbol as follows
0us us us 1
0us us us 1
Information ‘0’
Information ‘1’
Eunsung Park, LG Electronics

11. Straw Poll #3 Do you agree to add the following to the 11ba SFD?
January 2018
Straw Poll #3
Do you agree to add the following to the 11ba SFD?
The following is an example of a 2us ON-Signal generation process for the data rate of 250kbps
Apply the following 7-length sequence to every other subcarrier in contiguous 13 subcarriers, i.e. 1st,3rd,5th,7th,9th,11th and 13th subcarriers and set the others to zero
[1,-1,1,0,-1,-1,-1]
Perform 64-point IFFT and choose either the first or second 1.6us signal in a 3.2us signal with 1.6us periodicity
Prepend 0.4us GI
Eunsung Park, LG Electronics

12. January 2018
References
[1] IEEE /0575r6 Specification Framework for TGba [2] IEEE /0964r4 Signal Bandwidth and Sequence for OOK Signal Generation [3] IEEE /1625r1 Efficient FDMA MU Transmission Schemes for WUR WLAN [4] IEEE /1634r0 Optimizing OOK Waveform for High Data Rate WUR [5] IEEE /0376r0 Waveform Generation for Waveform Coding [6] IEEE /1615r0 Discussion on OOK Pulse Design for Higher Rate [7] IEEE /1144r0 Further Investigation on WUR Performance
Eunsung Park, LG Electronics

13. January 2018
Appendix
Eunsung Park, LG Electronics

14. Appendix A – PAPR and PSD for 4us ON-Signal
January 2018
Appendix A – PAPR and PSD for 4us ON-Signal
The following sequences are compared
Option 1 : [1,1,1,-1,-1,-1,0,-1,1,-1,-1,1,-1]
Option 2 : [1,-1,1,-1,-1,1,0,-1,-1,1,1,1,1] * (1+j)/sqrt(2)
Option 3 : [1,-1,1,1,1,1,0,1,-1,-1,1,1,-1]
Option 4 : [-1,-1,-1,1,1,-1,0,-1,-1,-1,1,-1,1]
PAPR [dB]
Option 1
Option 2
Option 3
Option 4
2.0611
2.2371
4.2759
3.9954
Eunsung Park, LG Electronics

15. Appendix A – PAPR and PSD for 4us ON-Signal
January 2018
Appendix A – PAPR and PSD for 4us ON-Signal
PSD
Option 1
Option 2
Option 3
Option 4
Eunsung Park, LG Electronics

16. January 2018
Appendix B – PAPR and PSD for 2us ON-Signal Generated by Masking Based Approach
The following sequences are compared
Option 1 : [1,1,1,-1,-1,-1,0,-1,1,-1,-1,1,-1]
Option 2 : [1,-1,1,-1,-1,1,0,-1,-1,1,1,1,1] * (1+j)/sqrt(2)
Option 3 : [1,-1,1,1,1,1,0,1,-1,-1,1,1,-1]
Option 4 : [-1,-1,-1,1,1,-1,0,-1,-1,-1,1,-1,1]
PAPR [dB]
Option 1
Option 2
Option 3
Option 4
First 2us ON-Signal
2.1228
2.1942
4.2783
3.9978
Last 2us ON-Signal
2.0003
2.2804
4.2734
3.9930
Eunsung Park, LG Electronics

17. January 2018
Appendix B – PAPR and PSD for 2us ON-Signal Generated by Masking Based Approach
PSD for the first 2us ON-Signal
Option 1
Option 2
Option 3
Option 4
Eunsung Park, LG Electronics

18. January 2018
Appendix B – PAPR and PSD for 2us ON-Signal Generated by Masking Based Approach
PSD for the last 2us ON-Signal
Option 1
Option 2
Option 3
Option 4
Eunsung Park, LG Electronics

19. The following two sequences are compared
January 2018
Appendix C – PAPR and PSD for 2us ON-Signal Generated by 64-Point IFFT Based Approach with 7-Length Sequence
The following two sequences are compared
Proposal : [1,-1,1,0,-1,-1,-1]
Partial STF sequence : [-1,-1,1,0,-1,-1,1]*(1+j)/sqrt(2)
PAPR
PSD
Proposal
Partial STF
2.2377
5.1927
Proposal
Partial STF
Eunsung Park, LG Electronics