[LAD] Determining Phase
Gordon JC Pearce
gordonjcp at gjcp.net
Sun Jun 26 22:02:38 UTC 2011
On Sun, 26 Jun 2011 14:54:48 -0400
gene heskett <gheskett at wdtv.com> wrote:
> I do not see how a repeatable, and therefore measurable quadrature
> component can be developed in a complex, multi-frequency waveform since the
> quadrature component is just as frequency dependent as any other method of
> measurement.
Really? Because I'm generating some quadrature samples right now - they're how software-defined radios work. In this case you generate two local oscillators 90 degrees apart and use them to switch a pair of synchronous detectors. The resulting downmixed RF is now at audio frequencies (just like a direct-conversion receiver) and can be passed to a soundcard, then processed on the PC to extract a particular signal.
See https://github.com/gordonjcp/lysdr if you want to play.
Gordon MM0YEQ
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