[ath9k-devel] Ath9k MIMO Performance versus Proprietary Drivers

[Felix Fietkau <nbd@openwrt.org>]

On 2010-02-24 8:22 PM, Galen wrote:
> This is an addendum to my earlier reply.
> 
> On Feb 22, 2010, at 1:09 PM, Felix Fietkau wrote:
>>>> Except for STBC, ath9k seems to have pretty much the same hardware
>>>> features as Atheros' other drivers. There may be some workarounds for
>>>> various hw issues missing, I have not extensively reviewed that yet.
>>> I would be interested in knowing more about these. LDPC? Others?
>>> There appear good software implementations of LDPC out there:
>>> http://planete-bcast.inrialpes.fr/article.php3?id_article=7
>> I'm pretty sure the current hardware also doesn't do LDPC yet.
> 
> I have looked over data presented on the Atheros website and as best as I can tell, the AR5008 (and other newer chipsets, I assume) support:
> 
> - STBC (space-time block coding) for TX and RX
> - MRC (maximal ratio combining) via zero forcing algorithm 
> - TxBF (transmit beam forming) 
> 
> From what you're saying, my understanding is that MRC and and TxBF
> are both functioning with ath9k, with STBC being the primary
> remaining feature. Is this correct?
TxBF isn't supported by the currently available hardware, so ath9k
doesn't make use of it either. I don't know about MRC, but I don't see a
difference between ath9k and other Atheros drivers in that area.
So yes, of those options, only STBC is missing.

- Felix