From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mailout1.informatik.tu-muenchen.de ([131.159.0.12]) by www.linuxtv.org with esmtp (Exim 4.63) (envelope-from ) id 1KuSdI-0002mh-5b for linux-dvb@linuxtv.org; Mon, 27 Oct 2008 14:59:49 +0100 Date: Mon, 27 Oct 2008 15:03:48 +0100 From: Georg Acher To: linux-dvb@linuxtv.org Message-ID: <20081027140348.GE9657@localhost> References: <412bdbff0810171104ob627994me2876504b43c18d8@mail.gmail.com> <49033440.6090609@gmx.de> <3cc3561f0810270337h4c33dd80n9b779a8dc3c8f8ce@mail.gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <3cc3561f0810270337h4c33dd80n9b779a8dc3c8f8ce@mail.gmail.com> Subject: Re: [linux-dvb] [RFC] SNR units in tuners List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: linux-dvb-bounces@linuxtv.org Errors-To: linux-dvb-bounces+mchehab=infradead.org@linuxtv.org List-ID: On Mon, Oct 27, 2008 at 10:37:52AM +0000, Morgan T=F8rvolt wrote: = > As I used to work with satellite signals on an earth station, and was > responsible for the development of measurement techniques, I thought I > should join in here for some hopefully revelaing info. > = > I am guessing here of course, but I believe that there is no real SNR > measurement in any of the tuners available for computers. = My guess is that it is possible. Actually, it is quite easy for QPSK ;-) You only need to calculate the distance of the IQ-value from the ideal symbol center ( (sqrt(0.5),sqrt(0.5)) or whatever) after the rotator/retiming-block. -- = Georg Acher, acher@in.tum.de http://www.lrr.in.tum.de/~acher "Oh no, not again !" The bowl of petunias _______________________________________________ linux-dvb mailing list linux-dvb@linuxtv.org http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb