Return-path: Received: from masada.superduper.net ([85.119.82.91]:48641 "EHLO masada.superduper.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751484Ab3ECVqu (ORCPT ); Fri, 3 May 2013 17:46:50 -0400 Message-ID: <51842836.8090601@superduper.net> (sfid-20130503_234653_881193_E37FBCD0) Date: Fri, 03 May 2013 14:12:22 -0700 From: Simon Barber MIME-Version: 1.0 To: Oleksij Rempel CC: radiotap@NetBSD.org, johannes@sipsolutions.net, Adrian Chadd , "ath9k-devel@lists.ath9k.org" , linux-wireless@vger.kernel.org Subject: Re: Standardisation - adding 2 bit STBC and Ness to MCS References: <518127ED.9060900@rempel-privat.de> In-Reply-To: <518127ED.9060900@rempel-privat.de> Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: I did post example code as attachments to the suggested-fields page a few months ago. Click on 'attachments' to view them. There are 3: 1. Intel wlan driver patch 2. Kernel patch 3. Wireshark patch. Simon On 05/01/2013 07:34 AM, Oleksij Rempel wrote: > Hallo all, > > >> http://www.radiotap.org/suggested-fields/MCS%20extension%20for%20STBC%20and%20Ness >> >> >> I have posted 3 patches on the proposal page (see Attachments): >> >> 1. A patch that applies to the Linux kernel v3.7-rc1 to collect the new >> STBC and Ness parameters from a wireless driver, and add them into the >> MCS radiotap field. >> 2. A patch to the Intel wireless driver in the kernel to collect STBC >> and Ness information. >> 3. A patch to wireshark to display STBC and Ness information. >> >> With this I believe we have everything needed to start the 3 week >> comment period. > > There is a bit more then 3 week now. I would like to have this approved :) > Are there any thing needed to finish this? > > Beside, i have one question about how STBC work. According to differnet > docs, i assume that: > - STBC is done by sending, at least, two stream with same data in > different order. > - It means for me, that real use of STBC can be made only on MIMO hardware. > - If 1x1 receiver indicates that it got STBC encoded frame, it dos not > meant, it would be able to use redundant data from second stream. > - There are fallowing STBC schemes: Alamouti’s > STBC for 2 transmit antennas and orthogonal STBC for 3 and 4 transmit > antennas. > > According to this information, what do we call 1,2 or 3 stream STBC? > Since STBC should have minimal 2 stream, but in same time we have 1x1 > and 2x2 hardware which able to receive and decode STBC stream i assume: > - RX-STBC1 is for compatibility only. No data redundancy. > - RX-STBC12 - can be used Alamouti’s schema with 2 streams. Mostly > used method. > - RX-STBC123 - is orthogonal schema and not widely used method. > Since last method use wide spectrum to transmit data comparable to SISO > stream, it makes almost no sense. But 3-stream method get optimal error > corect in compare with 2 and 4 strea schemas. > > Do this assumptions correct? > > PS: My assumptions based on "MIMO Space-Time Block Coding (STBC): > Simulations and Results"