Return-path: Received: from mout.gmx.net ([212.227.15.15]:59114 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751525Ab3EAOeZ (ORCPT ); Wed, 1 May 2013 10:34:25 -0400 Received: from mailout-de.gmx.net ([10.1.76.17]) by mrigmx.server.lan (mrigmx002) with ESMTP (Nemesis) id 0MARmu-1Uj4Qc1nA2-00Bbgg for ; Wed, 01 May 2013 16:34:24 +0200 Message-ID: <518127ED.9060900@rempel-privat.de> (sfid-20130501_163429_258127_95B38403) Date: Wed, 01 May 2013 16:34:21 +0200 From: Oleksij Rempel MIME-Version: 1.0 To: radiotap@NetBSD.org, simon@superduper.net, johannes@sipsolutions.net, Adrian Chadd CC: "ath9k-devel@lists.ath9k.org" , linux-wireless@vger.kernel.org Subject: Re: Standardisation - adding 2 bit STBC and Ness to MCS Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: 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" -- Regards, Oleksij