From 0d934b4fd23efe35b6264b68c8490b15992bfcc7 Mon Sep 17 00:00:00 2001 From: Michael Ossmann Date: Wed, 3 Jul 2013 21:50:28 -0700 Subject: [PATCH] Updated FAQ (markdown) --- FAQ.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/FAQ.md b/FAQ.md index db59dbf..2aa15b8 100644 --- a/FAQ.md +++ b/FAQ.md @@ -44,7 +44,7 @@ You are seeing a DC offset (or component or bias). The term "DC" comes from "Di ``` -2, -1, 1, 6, 8, 9, 8, 6, 1, -1, -2, -1, 1, 6, 8, 9, 8, 6, 1, -1, -2, -1, 1, 6, 8, 9, 8, 6, 1, -1 ``` -This periodic signal contains a strong sinusoidal component spanning from -2 to 9. If you were to plot the spectrum of this signal, you would see one spike at the frequency of this sinusoid and a second spike at 0 Hz (DC). If the signal were centered around 0, there would be no DC offset. Since it is centered around 3.5 (the number midway between -2 and 9), there is a DC component. +This periodic signal contains a strong sinusoidal component spanning from -2 to 9. If you were to plot the spectrum of this signal, you would see one spike at the frequency of this sinusoid and a second spike at 0 Hz (DC). If the signal spanned from values -2 to 2 (centered around zero), there would be no DC offset. Since it is centered around 3.5 (the number midway between -2 and 9), there is a DC component. Samples produced by HackRF are measurements of radio waveforms, but the measurement method is prone to a DC bias introduced by HackRF. It's an artifact of the measurement system, not an indication of a received radio signal. DC offset is not unique to HackRF; it is common to all quadrature sampling systems.