thank you for the insight. As you may have guessed, my generated IQ stream was made with a loop calling sin/cos and timing the transitions to times where I&Q can swap symmetrically ( without jumping ). what is then proper method for making phase transitions?
while there is a lot of documentation on what IQ data is, I've found very little documentation on proper generation ( trust me, I've looked) also do you recommend any references on filtering/post processing? also, thanks for spotting the data inversion, I'm sure I would have spotted it after I got it transmitted. On Jun 28, 2015 08:21, "Mike" <[email protected]> wrote: > I noticed that the generated sample is quite a lot smaller than the record > sample - I wonder whether there's a minimum buffer size somewhere that's > not being hit? Maybe try a larger generated file. > > I had a look at the sample files (spectrogram image attached, generated on > the left and recorded on the right) and noticed that the 0/1 frequencies > seem to be swapped. Also, it's a fantastic demo of why you need to apply > filtering to a transmitted signal: the extra vertical bars show the > harmonics and the horizontal bars show the wideband frequency content from > the sudden change in frequency. > > On 28 June 2015 at 02:43, Peter Shipley <[email protected]> wrote: > >> I am trying to transmit FSK2 at 915Mhz and can't figure out what I am >> doing wrong or what I am missing. >> >> I am trying to transmit a generated FSK2 signal. >> (Specs : freq=914973000, sample rate=2400000, FSK2 data with a >> deviation of 15000 ) >> >> >> I can record and transmit a replay without problems >> but I can't transmit my own generated IQ data. >> >> the hackrf device does not transmit anything at all when I send my IQ >> data >> (I can demodulate both localy with out error ) >> >> can someone clue me on what I missed or what is wrong with my IQ data >> >> I have included recorded sample (that will transmit) and and >> generated sanple (that wont transmit ) >> along with gnuplots of the data. >> >> >> https://drive.google.com/folderview?id=0B9v7L0HOe0FsfklXSFF0WUpIQzE4QUpRUzIzZXlsTUxXUFBPcWtzUGpmSlV3RTRGa1duaTA&usp=sharing >> _______________________________________________ >> HackRF-dev mailing list >> [email protected] >> https://pairlist9.pair.net/mailman/listinfo/hackrf-dev >> > >
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