From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luis R. Rodriguez Date: Fri, 26 Feb 2010 13:46:17 -0800 Subject: [ath9k-devel] Ath9k MIMO Performance versus Proprietary Drivers In-Reply-To: <625DED73-C678-459F-A529-67852AEE0D84@zinkconsulting.com> References: <4B8294B2.2020102@openwrt.org> <681BFE1D-4452-45B6-9E87-B2C21A50F2C5@zinkconsulting.com> <4B82F274.1000901@openwrt.org> <4B857EEF.6070003@openwrt.org> <20100225003940.GK13779@tux> <2484B0B7-E3E2-491A-B833-2CDD70C5ADC9@zinkconsulting.com> <20100226164555.GB3802@tux> <625DED73-C678-459F-A529-67852AEE0D84@zinkconsulting.com> Message-ID: <20100226214617.GL3802@tux> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ath9k-devel@lists.ath9k.org On Fri, Feb 26, 2010 at 12:45:02PM -0800, Galen wrote: > > On Feb 26, 2010, at 8:45 AM, Luis R. Rodriguez wrote: > > > On Thu, Feb 25, 2010 at 09:37:12PM -0800, Galen wrote: > >> On Feb 24, 2010, at 4:39 PM, Luis R. Rodriguez wrote: > >>> MRC is supported on all 11n chipsets, but not for cck rates. > >>> TX beamforming is only supported on the shiny new AR93xx > >>> chipsets. TX beamforming seems to have been supported on > >>> some old legacy chipset but there is no code to support it > >>> and I wouldn't bother trying. > >>> > >>> Luis > >> > >> > >> Luis - can you comment on the MRC implementation? Is this entirely > >> invisible to ath9k, or is this implemented / supported in software? > > > > No, frankly this is the first time I read about MRC. > > I just poked a few guys here about MRC and got the clarification > > above. > > Right - so the MRC functionality is in the chip's DSP and entirely > invisible to the software? Yes? Just being 100% clear here... Beats me. I haven't dealt with MRC at all in software so I guess. > >> And to be clear, you think the 802.11n chipsets before the > >> AR9300 *do not* include TxBF at all? Not that it simply isn't > >> supported by the drivers? > > > > Only a legacy (802.11g) end of life'd device had some form > > of Tx beamforming, but that's not even supported and its easier > > to just assume no chipset supports it other than the shiny > > new AR93xx family. > > Right - and as discussed, TxBF has less benefit than with 802.11n. Oh? > Since then, I have looked at some Matlab simulations here and seeing > that 2 antenna MRC can slightly outperform 2 antenna TxBF. Good to know, can you publish your results while at it. Luis