[linux-dvb] [RFC] SNR units in tuners

[Georg Acher]

On Mon, Oct 27, 2008 at 10:37:52AM +0000, Morgan Tørvolt 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 at in.tum.de
         http://www.lrr.in.tum.de/~acher
         "Oh no, not again !" The bowl of petunias