On 11/22/2014 06:01 PM, Marcus Müller wrote: > Hi zs, > hm, there's basically three places (that I know of) that GR uses Schmidl > & Cox: > the ofdm_chanest Channel estimator, the original S&C-based > ofdm_sync_pn.py and the more robustness-optimized version in > ofdm_sync_pnac.py. > I suspect you're referring to one of the two ofdm_sync_pn*.py , but they > differ a bit in how they deal with the peaks. Thus: > Which implementation are you referring to exactly?
He's probably referring to plateau_detector_fb. > Generally, Schmidl & Cox [1] states that > "The timing metric reaches a plateau [...] For the AWGN channel, there > is a window with a length of the guard interval where the metric reaches > a maximum, and the start of the frame can be taken to be anywhere within > this window without a loss in the received SNR." > Thus, without having really read throu ofdm_sync_pn.py in depth, if > using the original approach, you shouldn't even care where the plateau > is converted to a 1. This. Also, how do you detect plateaus? Have a look at the code. Finding the middle is easy, but how do you know you're at the beginning? M _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
