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RE: CA analysis between CSS and 11g



Rainer,

	I do not recall of the discussion regarding frequency offset.  I
guess my question to you is,

	Does 15.4a automatically select a channel so that it is never
co-channel with 802.11?

	If this is true then there is no need to evaluate co-channel
interference.  However, if that is not the case then I would think it
would make sense to look at co-channel interference.

Steve

-----Original Message-----
From: Rainer Hach [mailto:R.Hach@nanotron.com] 
Sent: Tuesday, June 13, 2006 8:50 AM
To: Shellhammer, Steve
Cc: Benjamin A. Rolfe; pat.kinney@ieee.org; Jay Bain; John Lampe;
Kyung-Kuk Lee; stds-802-19@ieee.org
Subject: RE: CA analysis between CSS and 11g

Steve,
thanks for your response.
Please see my answers below.
Best regards
Rainer

> -----Original Message-----
> From: Shellhammer, Steve [mailto:sshellha@qualcomm.com] 
> Sent: Monday, June 12, 2006 10:15 PM
> To: Rainer Hach
> Cc: Benjamin A. Rolfe; pat.kinney@ieee.org; Jay Bain; John 
> Lampe; Kyung-Kuk Lee; stds-802-19@ieee.org
> Subject: RE: CA analysis between CSS and 11g
> 
> 
> Rainer,
> 
> 	A few comments on the section coexistence with 11g.
> 
> 1.	I think the approach you took incorporating the coding gain into
> the
> 	BER formula is a reasonable approximation.  Clearly, it 
> is not exact,
> 	but probably close enough.
>
>>>>> Thanks for the confirmation!
> 
> 2.	The titles for the plots on page 16-18 are labeled "@6 MHz" when
> I a
> 	more accurate title would be "@ 6 Mb/s" since the data 
> rate changes
> 	not the bandwidth.
>>>>> Thanks for hint. We will correct this.
> 
> 3.	I am glad to see you included curves for 10% duty cycle.
> 
> 4.	In these curves (and also all the other curves in the document)
> you do
> 	not include co-channel interference (Foffset = 0 MHz).  
> Is there are
> 	reason for that?  It seems like it is possible for it to occur
> in 	practice, since for example 802.11 can be deployed to occupy
> three 	channels (1, 6 and 11).
>
>>>>> After our dicussion in Jacksonville I had the undestanding that
you agree that in case of all 3 nonoverlapping channels being >>>>>
occupied by 802.11 the reasonable strategy for CSS would be to use one
of the overlapping channels inbetween two nonoverlapping >>>>> channels.
Did I get this wrong?
> 
> 5.	Update the date on the document.
>
>>>>> Sorry for the wrong date!
> 
> Regards,
> Steve
> 
> -----Original Message-----
> From: Rainer Hach [mailto:R.Hach@nanotron.com] 
> Sent: Monday, June 12, 2006 7:17 AM
> To: Shellhammer, Steve
> Cc: Benjamin A. Rolfe; pat.kinney@ieee.org; Jay Bain; John 
> Lampe; Kyung-Kuk Lee
> Subject: RE: CA analysis between CSS and 11g
> 
> Steve,
> I would like to notify you that 15-06-0214-01-004a-CSS-CA-document.doc
> has been posted to the wirless server.
> Analysis for the coexistence between CSS and 11g has been 
> appended in this revision.  Additional frequency offset 
> values and duty cycle assumptions of 1% and 10% have been 
> used in the new section. Some details und curve shapes might 
> still change but basically that's what we intend to provide. 
> If you agree that this analysis is sufficient for 11g, we 
> will update the analyses for the other systems accordingly. 
> Please take a look and let us know. Best regards, Rainer
> 
> 
> > -----Original Message-----
> > From: Shellhammer, Steve [mailto:sshellha@qualcomm.com]
> > Sent: Wednesday, May 31, 2006 9:01 PM
> > To: Rainer Hach; Sheung Li
> > Cc: pat.kinney@ieee.org; stds-802-19@ieee.org; 
> > Joseph.Levy@interdigital.com; Kyung-Kuk Lee
> > Subject: RE: CA analysis between CSS and 11g
> > 
> > 
> > Rainer,
> > 
> > 	That should work for an AWGN channel.  I we have some
> > simulation results that would even be better.
> > 
> > Steve
> > 
> > -----Original Message-----
> > From: Rainer Hach [mailto:R.Hach@nanotron.com]
> > Sent: Wednesday, May 31, 2006 3:33 AM
> > To: Shellhammer, Steve; Sheung Li
> > Cc: pat.kinney@ieee.org; stds-802-19@ieee.org;
> > Joseph.Levy@interdigital.com; Kyung-Kuk Lee
> > Subject: RE: CA analysis between CSS and 11g
> > 
> > Steve, Sheung,
> > Coming back to the question for a BER equation for 11g I
> > wonder whether the following would make sense: Identify the 
> > modulation and code rate for the data rate in question (e.g 
> > 16QAM, R=1/2 for 24Mbit/s), calculate the partial BER (for on 
> > subcarrier) by using the textbook equation and reasonable 
> > coding gain for a convolutional code with k=7 and finally 
> > calculate the BER by assuming the 53 subcarriers to transport 
> > independent bit streams. Would this approach be acceptable? 
> > Best regards, Rainer
> > 
> > > -----Original Message-----
> > > From: Shellhammer, Steve [mailto:sshellha@qualcomm.com]
> > > Sent: Tuesday, May 30, 2006 10:33 PM
> > > To: Rainer Hach; Sheung Li
> > > Cc: pat.kinney@ieee.org; stds-802-19@ieee.org;
> > > Joseph.Levy@interdigital.com; Kyung-Kuk Lee
> > > Subject: RE: CA analysis between CSS and 11g
> > > 
> > > 
> > > Rainer,
> > > 
> > > 	I don't recall my statement about mid range, but that
> > > was two weeks ago.  Yes, if one is trying to represent
> > > typical then 24 Mb/s seems like a reasonable choice.
> > > 
> > > Steve
> > > 
> > > -----Original Message-----
> > > From: Rainer Hach [mailto:R.Hach@nanotron.com]
> > > Sent: Tuesday, May 30, 2006 9:13 AM
> > > To: Sheung Li; Shellhammer, Steve
> > > Cc: pat.kinney@ieee.org; stds-802-19@ieee.org;
> > > Joseph.Levy@interdigital.com; Kyung-Kuk Lee
> > > Subject: RE: CA analysis between CSS and 11g
> > > 
> > > Sheung,
> > > I am actually trying to get a better understanding of 11g. In the 
> > > 802.11 handbook, it says that the mandatory data rates 
> for OFDM are 
> > > 6,12 and 24 Mbits/s. The 54Mbit/s is optional but 
> required for Wi-Fi 
> > > certification. Is this information correct?
> > > 
> > > Steve, were you thinking of the 24Mbit/s OFDM mode when you 
> > > suggested the mid range data rate in our discussion in 
> Jacksonville? 
> > > Best regards, Rainer
> > > 
> > > > -----Original Message-----
> > > > From: Sheung Li [mailto:sheung@atheros.com]
> > > > Sent: Friday, May 26, 2006 3:54 PM
> > > > To: Rainer Hach
> > > > Cc: sshellha@qualcomm.com; pat.kinney@ieee.org;
> > > > stds-802-19@ieee.org; Joseph.Levy@interdigital.com
> > > > Subject: RE: CA analysis between CSS and 11g
> > > > 
> > > > 
> > > > Let me know what information you need.  Most of it should
> > be on the
> > > > IEEE802 CD-ROM.
> > > > 
> > > > The optional 22Mbps rates don't use OFDM, and are not widely
> > > > supported, so CA analysis isn't required.  You should 
> > take a look at
> > > > the extremes of the mandatory CCK-OFDM rates such as 6Mbps and
> > > > 54Mbps.
> > > > 
> > > > ==S
> > > > 
> > > > > -----Original Message-----
> > > > >From: Rainer Hach [mailto:R.Hach@nanotron.com]
> > > > > Sent: Fri 5/26/2006 1:18 AM
> > > > > To: Shellhammer, Steve
> > > > > Cc: pat.kinney@ieee.org; Kyung-Kuk Lee;
> > > > >stds-802-19@ieee.org; Sheung Li; Joseph.Levy@interdigital.com
> > > > > Subject: RE: CA analysis between CSS and 11g
> > > > > 
> > > > > Steve,
> > > > > thank you for your email.
> > > > > Does it mean that there is no 22Mb/s using OFDM?
> > > > > If so, which data rate do you feel is the most relevant
> > to assume
> > > > >for  11g?
> > > > > Also, could you please let me know the email address 
> of Sheung 
> > > > >Li?  Best regards,
> > > > > Rainer
> > > > > 
> > > > > 
> > > > >> -----Original Message-----
> > > > >> From: Shellhammer, Steve [mailto:sshellha@qualcomm.com]
> > > > >> Sent: Wednesday, May 24, 2006 8:05 PM
> > > > >> To: Rainer Hach
> > > > >> Cc: pat.kinney@ieee.org; Kyung-Kuk Lee;
> > > > >>stds-802-19@ieee.org;
> > > > >> sli@sibeam.com; Joseph.Levy@interdigital.com
> > > > >> Subject: RE: CA analysis between CSS and 11g
> > > > >> 
> > > > >> 
> > > > >> Rainer,
> > > > >> 
> > > > >> 	IEEE 802.11g is primarily based on OFDM.  There is a 22
> > >  Mb/s PHY
> > > > >>using PBCC.  However, that PHY is optional and not  widely 
> > > > >>deployed.  So my personal opinion is that analysis of
> > > > >> the 22 Mb/s PHY is probably unnecessary.  However, 
> > > > >> consideration of the OFDM PHY would be very important.
> > > > >> 
> > > > >> 	If you need some more details on the OFDM PHY you might
> > >  be able
> > > > >>to get some assistance from Sheung Li our liaison to
> > 802.11.  I
> > > > >>believe BER curves should be available.
> > > > >> 
> > > > >> 	Comment to TAG: In general, maybe if we can start to
> > > compile some
> > > > >>of this information we can put it in a common
> > > > >> place.  How about the document that Joseph Levy started?
> > > > >> 
> > > > >> Steve
> > > > >> 
> > > > >> -----Original Message-----
> > > > >> From: Rainer Hach [mailto:R.Hach@nanotron.com]
> > > > >> Sent: Wednesday, May 24, 2006 7:09 AM
> > > > >> To: Shellhammer, Steve
> > > > >> Cc: pat.kinney@ieee.org; Kyung-Kuk Lee
> > > > >> Subject: CA analysis between CSS and 11g
> > > > >> 
> > > > >> Steve,
> > > > >> thanks for your all your input in Jacksonville.
> > Considering 11g
> > > > >>with 22MBPS I am looking for a BER or PER
> > > > >> equation. One approch could be to figure out how many
> > > > >>sub 
> > > > >> carriers with which mdoulation and coding are used and 
> > > > >>then 
> > > > >> combine the BERs for each subcarrier. Is that 
> > > > >>appropriate? If 
> > > > >> so, can you help me with the assumptions on subcarriers 
> > > > >>etc. 
> > > > >> out or can you tell me somebody who could possibly do so 
> > > > >>or 
> > > > >> recommend some document besides the standard itself? 
> > > > >>Thanks! 
> > > > >> Best regards, Rainer
> > > > >> 
> > > > >> www.nanotron.com
> > > > >>  
> > > > >> 
> > > > > 
> > > > 
> > > > 
> > > 
> > 
>