I supposed I can reconstruct a virtual local oscillator by looking at the zero crossings and syncing a sine generator to that and then using the sine generator to determine the sign (making it a sign generator ;-P). Then my entire waveform might be inverted, but that is probably not much of a concern (at least for my needs).
Please tell me there is a better way. > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf > Of Bahn William L Civ USAFA/DFCS > Sent: Thursday, August 16, 2007 5:57 PM > To: discuss-gnuradio@gnu.org > Subject: [Discuss-gnuradio] Recovering x(t) from IQ samples > > If my i(t) and q(t) samples are defined as follows: > > i(t) = x(t) * sin(wt) > q(t) = x(t) * cos(wt) > > then, given i(t) and q(t), I can recover the magnitude of x(t) as follows: > > |x(t)| = sqrt(i^2(t) + q^2(t)) > > But how can I recover the sign of x(t)? For each of the four possible > combinations of the signs of i(t) and q(t), x(t) could be either positive > or negative. > > Thanks. > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
