Re: stds-802-16-tg4: Need for RF input to TG4 PHY specs
If you want to get the range advantage of the advanced FEC I think the SNR
target should be around 2dB.
It may be preferable to make that target optional since advanced FEC will
(most likely) be optional as well.
-Brian Edmonston
----- Original Message -----
From: Drayt Avera <davera@rf-solutions.com>
To: Stds-802-16-Tg4@Ieee. Org <stds-802-16-tg4@ieee.org>
Sent: Thursday, May 03, 2001 7:17 AM
Subject: stds-802-16-tg4: Need for RF input to TG4 PHY specs
> TG4 Team,
> Here are some items which need to be addressed in the TG4 spec. Let's get
a
> dialog started and try to solidify some numbers prior to the meeting in a
> few weeks.
>
> 1) Need specs for the expected interference conditions or protection
> requirements. In 802.11a minimal adjacent channel specs are specified,
and
> I would think we would need greater interference protection. Some
possible
> specs to add:
> minimum adjacent channel protection (about 40dB?) vs channel bandwidth
> selected
> alternate adjacent channel protection
> TBD MHz blocking (jamming protection)
> max expected receiver level (in-band and out of band)
>
> 2) Transmit or receive linearity requirements should be specified. The
> receiver linearity will impact the system design for near/far issues. On
> the transmit side, maybe an EVM measurement under standard conditions
> (similar to 802.11a) make more sense.
>
> 3) Need to determine a sensitivity requirement. Depending on the
> interference and linearity requirements it should be around 5-6dB. What
SNR
> is required for the various modulation methods? I think a table of
minimum
> sensitivity vs channel bandwidth would be most appropriate.
>
> 4) Adjustment range for power control and any Rx AGC including response
> characteristics and resolution. There were some previous responses
showing
> around 30-40dB, and it would be good to discuss the calculations that
anyone
> has done. 802.11a has requirements for the Tx flatness of +/-2dB.
>
> 5) Tx flatness: are the 802.11a requirements good enough?
>
> 6) Should we have a Clear Channel Assessment (CCA) type function and a
> threshold to transmit?
>
> 7) TDD and FDD coexistence strategy. Are most of you are headed towards
> TDD?
>
> 8) Phase noise requirement: Is this buried in the EVM measurement? It
> would be simpler to specify it directly.
>
> 9) Are there any group delay requirements (absolute or variation)?
>
> 10) Some misc items need to be addressed:
> temp range: same as 802.11a but add Type 4= -40 to +85C
> Tx and Rx antenna port impedance=50ohms
>
> 11) What hooks are needed for frequency diversity/MIMO, etc... TJ, are
you
> including these in the future enhancements section?
>
> 12) Do you see most systems being 1 or 2 box solutions? If 2 boxes,
should
> add some recommended practice for standardization.
>
> Let's get a dialog going and I'll try to provide a coordinated input to
the
> PHY spec.
>
> Regards,
> Drayt
>
>