[Hackrf-dev] transmitting problem

[Michael Ossmann]

On Sun, Jun 28, 2015 at 08:49:40AM -0700, Peter Shipley wrote:
>
> 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?

One method is to smoothly lower the amplitude to zero at the transition
and then back up to full amplitude by mid-symbol.  This is done, for
example, in PSK31.  A simpler approach is to use an FIR low pass filter
on your waveform before transmission.

Mike