These are chat archives for Opendigitalradio/mmbTools

4th
Jun 2016
Matthias P. Braendli
@mpbraendli
Jun 04 2016 07:44
Looks like very slow fading, as if the two signals had a very small frequency difference. I know that in real SFN networks you can have reception problems in places where you receive two signals with same amplitude and in phase, you could have similar effects. What happens if you delay (e.g. 3us) one transmission compared to the other?
Glad to see you are doing SFN experiments on your side :-)
piratfm
@piratfm
Jun 04 2016 10:14

When I use 10MHz from single receiver - then the picture is static, like one of shoulder is smaller than another all the time (but it seems like it can be fixed by tuning PLL's phase). My measurement receiver - is exactly "in the middle of simulation", when both signals with equal powers are mixed and received in the middle.

In most cases 1PPS signal's difference - is around ~60ns, when i add 3us delay, the picture became like this:
3us

Yep, I'm ready to release new sources and needed modifications to use the board with GPSDO just waiting for another one receiver from cellular base station.

Also when added 3us delay, the constellation map starts looks like X letter.