Dear Martin, I wondered, if you are working on the HPD, if it's possible to look into making a change when a header is received incorrectly, e.g. low SNR or sudden shadowing. I find that (although it no longer crashes with the recent update to adjust buffer size) it loses synchronisation and does not recover in later packets. I can't quite work out why...
Regards, David From: discuss-gnuradio-bounces+david.halls=toshiba-trel....@gnu.org [mailto:discuss-gnuradio-bounces+david.halls=toshiba-trel....@gnu.org] On Behalf Of Aditya Dhananjay Sent: 22 January 2014 15:02 To: Martin Braun Cc: discuss-gnuradio@gnu.org Subject: Re: [Discuss-gnuradio] header_payload_demux_impl.cc - problem when using random bit stream (variable trigger location) Dear Martin, Thanks for the ideas. Two ideas: - You could remove the sync block and sync your rx/tx paths with other means (e.g. MIMO connector, it depends on your hardware). This makes the sync influence independent of the noise. Good idea, I will try it out once I get the cables. - Reconsider if the phase rotation really makes your measurements invalid. You'll have a phase rotation in any case (due to channel, propagation time etc.). The timing-related phase offset is constant, after all, and the phase difference between sub-carriers depends on the sub-carrier distance, too. Perhaps it doesn't matter all that much? That makes sense. I want to study the different phenomena that affect phase rotations in the channel. By eliminating the USRP hardware (by connecting the TX and RX blocks to each other through a channel model block), I can control the PDP of the simulated channel, for example. Thank you for your inputs. This is very useful to me. best regards, aditya ________________________________ NOTE: The information in this email and any attachments may be confidential and/or legally privileged. This message may be read, copied and used only by the intended recipient. If you are not the intended recipient, please destroy this message, delete any copies held on your system and notify the sender immediately. Toshiba Research Europe Limited, registered in England and Wales (2519556). Registered Office 208 Cambridge Science Park, Milton Road, Cambridge CB4 0GZ, England. Web: www.toshiba.eu/research/trl --------------------------------------------------------------------------------------- This email has been scanned for email related threats and delivered safely by Mimecast. For more information please visit http://www.mimecast.com ---------------------------------------------------------------------------------------
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