Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

Re: [STDS-802-11-TGAZ] IEEE submission 11-19/1572r4

Thank you all for joining in the call and discussions. 

Hi Feng,

Thanks for the mail and comments. 

1. This is easy to simulate. The max theoretical loss in SNR (i.e., the loss, compared to that of perfectly known channel) can also be quantified to \sqrt(1+1/L) where the L the length of the LTF. The default here is L=2.  The scenario in discussion is when half of that is nulled out due to destructive interference. This effectively becomes a loss of 20*log10(sqrt(1+1/1))-20*log10(sqrt(1+1/2)) ~ 1.25dB.  I guess this is a well known result. If you wish, I can send you small write up, or we can discuss this at Hawaii. We didn’t quantify the ranging performance per se here, but as you know, it will get hurt. The larger worry is on the receiver dynamic range requirements, which we believe is an important thing to get fixed. 
2. Yes, it is true that, we can get back the lost gain in channel estimation, by repeated HE-LTF, but this is simply a round about way of wasting resources, by not addressing the problem which can be easily solved in the first place. On the other hand, with repeated LTF option in place, we can enhance the performance even further, if we resolve the nulling problem. As you can see, the fix on the table is much easier!
3. Thanks. Yes, Shall fix this. 

Anyway the moot point is: Should we leave a hole in the spec, which in turn necessitate over designing the receiver? In principle, yes, we can budget a lot more head room (e.g., ADC requirements as Christian mentioned) and circumvent this by employing expensive solutions.  IMO, it is not a good idea to limit potential future products, which can otherwise be designed economically. A car key fob is a great example. It may not be a viable option on such product line to have a 12 bit ADC. May be we can even make it work with 8 bit or even 6 bit ADC, depending on the market it cater to. 

We can as well fix this right now by addressing the problem, instead of unnecessarily burdening the receiver.  And a great side benefit is that, we make the ranging even more more secure:-)

Regards,
Rethna. 

On Wed, Oct 16, 2019 at 8:46 PM Jiang, Feng1 <feng1.jiang@xxxxxxxxx> wrote:

Hi Christian,

 

Do you mean it’s not practical to further tune the AGC gain based on the fading information obtained from L-LTF? What is the limitation for processing delay and timing?

Also for the less bits ADC, how many bits do you assume? How much the SNR/ranging accuracy will be lost for such a less bit ADC? Thanks.  

 

Best regards,

 

Feng Jiang

 

From: Christian Berger [mailto:crberger@xxxxxxxxxxx]
Sent: Wednesday, October 16, 2019 6:41 PM
To: Jiang, Feng1 <feng1.jiang@xxxxxxxxx>; STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Cc: Li, Qinghua <qinghua.li@xxxxxxxxx>; Segev, Jonathan <jonathan.segev@xxxxxxxxx>
Subject: RE: IEEE submission 11-19/1572r4

 

Estimating the channel on the legacy-LTF and adjusting the ADC setting on the HE preamble accordingly is unfortunately not practical at all, if you are familiar with processing delays and timing.

 

Furthermore receiving 1024 QAM is not necessarily a standard feature available on all devices that might provide secure ranging, like a car key fob. Same devices will potentially have a lower performance (less bits) ADC. With such design choices, we are potentially precluding a lot of devices from using secure ranging or alternatively providing such poor receiver SNR that will not make the next generation of ranging accuracy possible.

 

Christian

 

From: Jiang, Feng1 <feng1.jiang@xxxxxxxxx>
Sent: Wednesday, October 16, 2019 5:29 PM
To: Christian Berger <crberger@xxxxxxxxxxx>; STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Cc: Li, Qinghua <qinghua.li@xxxxxxxxx>; Segev, Jonathan <jonathan.segev@xxxxxxxxx>
Subject: [EXT] RE: IEEE submission 11-19/1572r4

 

External Email

Hi Christian,

 

Thanks for your comments. In the ADC dynamic range design some margin need to be allowed to cover the PAPR of the received signal. For example, for 1024QAM the PAPR can be up to 10dB, and if the data packet can be received successfully with no saturation, then using the same AGC setting, the secured NDP frame should also be received correctly with no saturation. Additionally, the PAPR of the secured NDP frame is already optimized by several dB and this will be helpful for relaxing the dynamic range of ADC.

 

It seems not true that “The channel conditions will *not* be known a priori,” since the legacy preamble in the L-LTF field of NDPA or secured NDP frame can indicate whether it’s heavy fading or AWGN.

 

As shown in the submission 11-19/1572r4, the max SNR degradation of channel estimation due to this unintentional beamforming is 1.2494dB, and it may not hurt ranging performance too much. Unless we see significant ranging performance degradation, it’s better to keep the current secured NDP design unchanged for simplicity.

 

Best regards,

 

Feng Jiang

 

From: *** 802.11 TGaz - NGP - Next Generation Positioning *** [mailto:STDS-802-11-TGAZ@xxxxxxxx] On Behalf Of Christian Berger
Sent: Wednesday, October 16, 2019 5:02 PM
To: STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-11-TGAZ] IEEE submission 11-19/1572r4

 

Hi Feng,

 

There was a claim in the discussion today that the increased dynamic range will not be an issue since:

  • For line-of-sight channels the increased dynamic range requirements for the ADC will be 3/6/9 dB for 2/4/8 streams, but line-of-sight channels have good SNR
  • For heavy fading/ non-line-of-sight channels the increase in dynamic range will be much less, since intentional beamforming will be mitigated by the multipath

 

This is not true in practice, as to avoid saturation the ADC will have to back off an extra 3/6/9 dB after decoding the NDP-A /NPD SIGA and determining the number of streams/LTF. The channel conditions will *not* be known a priori, so for *any* secure NDP with multiple streams, including for heavy fading channels the ADC will have to back off sufficiently to avoid saturation.

 

So we are increasing the required dynamic range of the ADCs used in secure Ranging by 3/6/9 dB. This will carry through to baseband processing and FFT cores which usually rely on gain targets.

 

Christian

 

From: *** 802.11 TGaz - NGP - Next Generation Positioning *** <STDS-802-11-TGAZ@xxxxxxxx> On Behalf Of Jiang, Feng1
Sent: Wednesday, October 16, 2019 4:48 PM
To: STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Subject: [EXT] Re: [STDS-802-11-TGAZ] IEEE submission 11-19/1572r4

 

External Email

Hi Rethna,

 

Thanks for the good discussions in today’s TGaz telecon.

A few more questions/comments regarding 11-19/1572r4 are listed below for your review. Thanks.

 

  1. In slide 7, it stated the max SNR degradation for channel estimation due to unintentional beamforming is 1.2494 dB, and could you please show more details how this number is derived? Also, have you evaluated how much ranging performance will be degraded by this 1.2494dB SNR loss? If the ranging performance doesn’t suffer too much, then maybe we don’t need to worry about this unintentional beamforming issue in secured ranging.
  2. In secured NDP frame for ranging, the HE-LTF field is always repeated (at least two HE-LTF fields), and one repetition will provide 3dB additional gain after combining the channel estimation results. Even if there is 1.2494dB degradation for channel estimation of a single HE-LTF field, the 3dB gain of the repeated HE-LTF field will compensate it.
  3. In slide 27, a minus sign is missed before “h11_k“ in the equation “ y1[n+1] / A2k = h11_k + h12_k’ ”

 

 

Best regards,

 

Feng Jiang

 

From: *** 802.11 TGaz - NGP - Next Generation Positioning *** [mailto:STDS-802-11-TGAZ@xxxxxxxx] On Behalf Of Rethna Pulikkoonattu
Sent: Thursday, September 26, 2019 10:59 AM
To: STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-11-TGAZ] TGaz Oct. 2nd telecon

 

Hi Jonathan,

 

Could you also allocate a slot at the Oct 2nd, 2019 TGaz Telecon for the following submission?

11-19/1572r4, Secure-LTF: Unintentional Beamforming Problem and A Solution Proposal

 

Thanks and regards,

Rethna. 

 

On Thu, Sep 26, 2019 at 10:56 AM Segev, Jonathan <jonathan.segev@xxxxxxxxx> wrote:

Thank you both,

 

I will add this to the submission pipeline.

 

Best,

Jonathan

 

From: *** 802.11 TGaz - NGP - Next Generation Positioning *** [mailto:STDS-802-11-TGAZ@xxxxxxxx] On Behalf Of Venkatesan, Ganesh
Sent: Thursday, September 26, 2019 10:49
To: STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-11-TGAZ] TGaz Oct. 2nd telecon

 

Hello Jonathan:

 

Could you please add the following submissions to the agenda pipeline:

11-19-1686r0 – resolutions to a set of LB240 CIDs (part-7)

11-19-1368r2 -- resolutions to a set of LB240 CIDs (part-8)

 

Cheers --

ganesh

“It is amazing what you can accomplish if you don’t care who gets the credit.” – Harry Truman

 

 

From: *** 802.11 TGaz - NGP - Next Generation Positioning *** <STDS-802-11-TGAZ@xxxxxxxx> On Behalf Of Jiang, Feng1
Sent: Thursday, September 26, 2019 10:31 AM
To: STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-11-TGAZ] TGaz Oct. 2nd telecon

 

Hi Jonathan,

 

Could you please add the following submission to Oct. 2nd TGaz telecon? Part of this submission was presented in Hanoi meeting, but due to agenda time limitation, it was not completed.

We would like to finish the CR to the remaining 5 CIDs in the coming telecon. Thanks.

 

  • 11-19/1563R1 CR for Miscellaneous CIDs in LB240_part 2

 

Best regards,

 

Feng Jiang

 

From: *** 802.11 TGaz - NGP - Next Generation Positioning *** [mailto:STDS-802-11-TGAZ@xxxxxxxx] On Behalf Of Segev, Jonathan
Sent: Wednesday, August 28, 2019 12:03 PM
To: STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-11-TGAZ] TGaz Aug. 28th telecon

 

Thank you Ali, added to the submission queue.

 

From: qi_wang2@xxxxxxxxx [mailto:qi_wang2@xxxxxxxxx]
Sent: Tuesday, August 27, 2019 16:15
To: Segev, Jonathan <jonathan.segev@xxxxxxxxx>
Cc: STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-11-TGAZ] TGaz Aug. 28th telecon

 

Hi Jonathan, 

 

Would you please add the document “11-19-1460-00” to the presentation queue? It proposes resolutions to a few LB240 CIDs on DMG/EDMG ranging. 

 

Regards,

Qi

 

 

 

On Aug 27, 2019, at 2:41 PM, Das, Dibakar <dibakar.das@xxxxxxxxx> wrote:

 

Hi Jonathan,

 

I want to postpone discussion on “11-19-678 CR for CID 1115” till the FTF based on offline request.

 

 

Regards,

Dibakar

From: *** 802.11 TGaz - NGP - Next Generation Positioning *** [mailto:STDS-802-11-TGAZ@xxxxxxxx] On Behalf Of Ali Raissinia
Sent: Tuesday, August 27, 2019 2:01 PM
To: STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-11-TGAZ] TGaz Aug. 28th telecon

 

Hi Jonathan,

 

Please add document 11-19-1455-01 CR for 1118, 1129 and 1324 in the agenda queue in case we have time for me to present it.

 

Thanks,

Ali

 

From: *** 802.11 TGaz - NGP - Next Generation Positioning *** <STDS-802-11-TGAZ@xxxxxxxx> On Behalf Of Segev, Jonathan
Sent: Tuesday, August 27, 2019 1:28 PM
To: STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Subject: [STDS-802-11-TGAZ] TGaz Aug. 28th telecon

 

CAUTION: This email originated from outside of the organization.

Hello folks,

 

Agenda topics for tomorrow’s telecon is as follows:

•       11-19-678 CR for CID 1115 (Dibakar)

•       11-19-1422 Clause 11 PXDMG CIDs (Assaf)

 

Agenda document is submission 11-19-1362, be sure to use latest version.

Please let me know of any additional agenda topic you may have.

 

Best,

Jonathan

 

From: *** 802.11 TGaz - NGP - Next Generation Positioning *** [mailto:STDS-802-11-TGAZ@xxxxxxxx] On Behalf Of Segev, Jonathan
Sent: Tuesday, August 20, 2019 11:19
To: STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-11-TGAZ] TGaz Aug 21st Telecon agenda and call for submissions

 

Thank you Assaf, added to the queue.

 

From: Assaf Kasher [mailto:akasher@xxxxxxxxxxxxxxxx] 
Sent: Monday, August 19, 2019 23:47
To: Segev, Jonathan <jonathan.segev@xxxxxxxxx>; STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Subject: RE: TGaz Aug 21st Telecon agenda and call for submissions

 

Hi Jonathan,

Please add 11-19-1422-00-00az-Clause-11-PXDMG-CIDs to the queue.

I will need about 40 minutes to review it.

Thanks,

     Assaf

 

From: *** 802.11 TGaz - NGP - Next Generation Positioning *** <STDS-802-11-TGAZ@xxxxxxxx> On Behalf Of Segev, Jonathan
Sent: Tuesday, August 20, 2019 2:19 AM
To: STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-11-TGAZ] TGaz Aug 21st Telecon agenda and call for submissions

 

CAUTION: This email originated from outside of the organization.

 

 

Best,

Jonathan

 

From: Segev, Jonathan 
Sent: Monday, August 19, 2019 08:21
To: Das, Dibakar <dibakar.das@xxxxxxxxx>; STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Subject: RE: TGaz Aug 21st Telecon agenda and call for submissions

 

thank you Dibakar I will add this to the Wed. telecon agenda for this week.

 

From: *** 802.11 TGaz - NGP - Next Generation Positioning *** [mailto:STDS-802-11-TGAZ@xxxxxxxx] On Behalf Of Das, Dibakar
Sent: Monday, August 19, 2019 05:18
To: STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-11-TGAZ] TGaz Aug 21st Telecon agenda and call for submissions

 

Hi Jonathan,

 

Can you please add the following submission to the agenda:

“11-19-678r0- CR for CID 1115” ?

I will need about 30 minutes for discussion.

 

Regards,

Dibakar

 

From: *** 802.11 TGaz - NGP - Next Generation Positioning *** [mailto:STDS-802-11-TGAZ@xxxxxxxx] On Behalf Of Jiang, Feng1
Sent: Thursday, August 15, 2019 12:12 PM
To: STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-11-TGAZ] TGaz Aug 21st Telecon agenda and call for submissions

 

Hi Jonathan, 

 

Could you please add the following contribution to agenda? Thanks.

 

  • DCN 1438 CR for PHY related comments for LB240-part3

 

Best regards,

 

Feng Jiang

 

From: *** 802.11 TGaz - NGP - Next Generation Positioning *** [mailto:STDS-802-11-TGAZ@xxxxxxxx] On Behalf Of Segev, Jonathan
Sent: Wednesday, August 14, 2019 12:07 PM
To: STDS-802-11-TGAZ@xxxxxxxxxxxxxxxxx
Subject: [STDS-802-11-TGAZ] TGaz Aug 21st Telecon agenda and call for submissions

 

Hello all,

 

  1. TGaz telecon scheduled for Wed. Aug. 21st 13:00 ET/10:00AM PT for 1:30 hrs.

 

  1. Telecon agenda slide deck is submission 11-19-1362, be sure to use latest revision.

 

  1. If you’re planning a submission and would like to allocate agenda time please let me know.

 

  1. Note that teleconferences are bounded by the conditions stipulated by the documentation below.

Please review and bring up any questions/concerns you may have before proceeding with the teleconference:

 

Best Regards,

Jonathan Segev,

Cell (WhatsApp): +1-408-203-3337 (note # change)

 

 

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1

 

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1

To unsubscribe from the STDS-802-11-TGAZ list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGAZ&A=1