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From: | Marcus D. Leech |
Subject: | Re: [Discuss-gnuradio] UHD I/O Data Types |
Date: | Wed, 20 Apr 2011 20:04:09 -0400 |
User-agent: | Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.15) Gecko/20110307 Fedora/3.1.9-0.39.b3pre.fc14 Thunderbird/3.1.9 |
One could take that real sinusoid, and translate it into the complex plane with aYou cannot represent a "pure" sinusoid with a real signal. Think e^(jw) vs Re{e^(jw)} Maybe someone could think of a better way to say this. All USRP devices input and output complex baseband. You need to represent your signal in complex baseband. I suggest experimenting by feeding your signal into the _complex_ fft plotter in grc and see how it looks spectrally, because thats how your actual spectrum will look when you transmit, but shifted up by fc Hz. -Josh _
Hilbert transform, and there's a block for doing that.Although, if this is a pre-recorded signal, one could simply do the Hilbert transform "offline", and have the pre-recorded signal be already transformed into the complex
plane.But if Arya is already using a signal-generator block within GRC or C++, they could simply
use the already-existing complex output type.The hardware expects signals to be represented in the complex plane, even when there is no negative
frequency content of said signals. -- Marcus Leech Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org
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