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Date:      Thu, 10 Oct 2013 18:34:21 -0700
From:      Adrian Chadd <adrian@freebsd.org>
To:        w <tx2023@gmail.com>
Cc:        "freebsd-wireless@freebsd.org" <freebsd-wireless@freebsd.org>
Subject:   Re: Correlation values for Atheros adaptive noise immunity
Message-ID:  <CAJ-VmokPXbNadoDUMwoFK8_NVLy6stOB65UfH1Ht8AT7S4nXFg@mail.gmail.com>
In-Reply-To: <CAC6a1DiNuB5b14Qf4wtb6L1hS965A9bqqpbkxjX5pEk4d4QVUQ@mail.gmail.com>
References:  <CAC6a1DhqKPyJ5WvsP%2BtV_b5EcUGTwRHCnei=JA2-oSZCJFhAbw@mail.gmail.com> <CAJ-Vmo=TFrQOWGE-J7JK6-aciZcxoA1wgTFMHLLKXYK0ZgQGQw@mail.gmail.com> <CAC6a1DiBQY-Yg92%2B%2BssLthwZOoM7mZ4Y3xs%2BHj2uqcoSbV2h4g@mail.gmail.com> <CAC6a1DggX8KdfHnsWt-CvAq3ivMVTC99=64Whpj8ff%2BfPmnZPg@mail.gmail.com> <CAJ-Vmokwo=zELOCeSb8dL3v5=s%2BcetMzbD_wewBJ_TLEcCm28A@mail.gmail.com> <CAC6a1DiNuB5b14Qf4wtb6L1hS965A9bqqpbkxjX5pEk4d4QVUQ@mail.gmail.com>

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I don't have any open source PHY documentation. :) I'd have to write it.

Which isn't a bad thing; I'm happy to go and re-read what I (legally,
legitimately!) have from Atheros about their PHY design and ANI and write
up what's implemented in the driver.

The thing with ANI is that a lot of the parameters (like self-correlation
thresholds) have to do with how signal detection in the PHY works. So it's
not specifically noise immunity as much as it's tweaking the sensitivity
range and thresholds of the receiver hardware.

There's some interesting things that should be re-investigated (ie, the
m1/m2 thresholds and how weak signal detection works); I vaguely recall
when I was working there that ANI was doing it "wrong". I'll setup a
meeting or two with the PHY team when I'm back in California and jot down
some further notes about this.



-adrian

(note: so I'm legally allowed to have all this stuff and I'm legally
allowed to code up open source drivers with it, but what I can't do is
share the documentation I have. So no, I won't share it. But whatever goes
into open source to improve their chips is open/fair game. Hence, I can
write documentation and discuss whatever ends up in the open source
drivers..)



On 10 October 2013 18:30, w <tx2023@gmail.com> wrote:

> Do you have the open source link for the PHY documentation so I could rea=
d
> it?
>
> Actually my goal is quite simple I think: To test the effectiveness of AN=
I.
>
> Thanks very much.
>
> ~ w ~
>
> On Fri, Oct 11, 2013 at 4:43 AM, Adrian Chadd <adrian@freebsd.org> wrote:
> > Yeah, it's all a bit confusing. I'd have to re-read the PHY
> documentation i
> > have here in order to really understand whta's going on.
> >
> > What are you trying to achieve herE?
> >
> >
> > -adrian
> >
> >
> >
> > On 9 October 2013 20:03, w <tx2023@gmail.com> wrote:
> >>
> >> Update: looking at the patent again:
> >> http://www.freepatentsonline.com/7349503.html
> >>
> >> Note that bb_m1thres and bb_m2thres refer to normalized,
> >> self-correlated thresholds, bb_m2count_thr refers to the number of
> >> self-correlation values (wherein a typical count would not exceed 31),
> >> and bb_use_self_corr_low refers to an enabling bit value.
> >>
> >> (but the variables are still quite confusing.)
> >>
> >>
> >> ~ w ~
> >>
> >> On Thu, Oct 10, 2013 at 10:12 AM, w <tx2023@gmail.com> wrote:
> >> > Yup, I read the patent. I have also read the Atheros documentation f=
or
> >> > ANI (for a different hardware version but it says the operation is
> >> > similar).
> >> >
> >> > Are we able to see physical layer parameters like signal level /
> >> > correlation / channel state information,
> >> > or are they hidden inside the hardware?
> >> >
> >> > ~ w ~
> >> >
> >> >
> >> >
> >> > On Thu, Oct 10, 2013 at 10:05 AM, Adrian Chadd <adrian@freebsd.org>
> >> > wrote:
> >> >> I'm not sure. I think it's a signal level. Have you read the ANI
> >> >> patent(s) ?
> >> >>
> >> >>
> >> >>
> >> >> -adrian
> >> >>
> >> >>
> >> >>
> >> >> On 9 October 2013 19:04, w <tx2023@gmail.com> wrote:
> >> >>>
> >> >>> Is there any way I can printk the correlation values for
> ar5416_ani.c?
> >> >>>
> >> >>> I couldn=92t find the variable that contains the correlation value=
.
> >> >>> Line 267 of the ar5416_ani.c file says:
> >> >>> OS_REG_RMW_FIELD(ah, AR_PHY_SFCORR,
> >> >>> AR_PHY_SFCORR_M1_THRESH, m1Thresh[on]);
> >> >>>
> >> >>> I don=92t know what the variables mean or what the function means =
or
> >> >>> what data type the variables are because I want to printk them.
> >> >>>
> >> >>> References:
> >> >>>
> >> >>>
> >> >>>
> >> >>>
> http://svnweb.freebsd.org/base/head/sys/dev/ath/ath_hal/ar5416/ar5416_ani=
.c?view=3Dmarkup
> >> >>>
> >> >>> https://wiki.freebsd.org/dev/ath_hal%284%29/AutomaticNoiseImmunity
> >> >>>
> >> >>> ~ w ~
> >> >>> _______________________________________________
> >> >>> freebsd-wireless@freebsd.org mailing list
> >> >>> http://lists.freebsd.org/mailman/listinfo/freebsd-wireless
> >> >>> To unsubscribe, send any mail to
> >> >>> "freebsd-wireless-unsubscribe@freebsd.org"
> >> >>
> >> >>
> >> _______________________________________________
> >> freebsd-wireless@freebsd.org mailing list
> >> http://lists.freebsd.org/mailman/listinfo/freebsd-wireless
> >> To unsubscribe, send any mail to
> >> "freebsd-wireless-unsubscribe@freebsd.org"
> >
> >
>



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