----- Original Message ----- From: Patrick Lindecker To: [email protected] Sent: Saturday, August 25, 2007 7:21 PM Subject: [soft_radio] Mix the time domain Q & I signal with a NCO to make a near to zero signal
Hello Fred, Alberto and all, I'm investing an interesting time in the SdR theory. One particular message of this group makes me problem. The problematic sentence is the following: "1° Mix the time domain Q & I signal with a NCO to make a near to zero signal"(this before the FFT) It seems that the "NCO" must mean something as "numerical oscillator". I don't suppose that it is an analytic oscillator (cos wot / sin wot) but a simple oscillator (cos wot). This simple oscillator applies to I and Q. An NCO (numerically-controlled oscillator) is the same as a DDS. 'I' means 'in-phase' and 'Q' means 'quadrature'. Leon
