Sampling Complex Signal

On Thu, 9 Aug 2012 17:52:06 -0700 (PDT), Robert Adams
<robert.adams@analog.com> wrote:

>I tend to visualize the sampling theory as a convolution where the spectrum=
> of the sampling sequence (regularly spaced sticks) is convolved with the s=
>pectrum of the analog signal, which is double-sided if the signal is real. =
>Therefore you need a sample rate 2*fmax to avoid any aliasing. However if y=
>ou clear out one half of the signal spectrum by making it an analytic signa=
>l, you can make the sample-rate equal to fmax without any aliasing.  This i=
>s a nice visual that allows me to avoid math, since all the math fell out o=
>f my head around 1980 as far as I can tell.
>
>So I think the mistake the OP made was to assume that a signal is analytic =
>just because it's complex. While all analytic signals are complex, not all =
>complex signals are analytic.
>
>
>Bob
>

That's a good way of thinking about it that hadn't occurred to me.   I
may steal that.   ;)


Eric Jacobsen
Anchor Hill Communications
www.anchorhill.com

Robert Adams <robert.adams@analog.com> writes:
> [...]
> This is a nice visual that allows me to avoid math, since all the math
> fell out of my head around 1980 as far as I can tell.

"Fell out of my head?" ... LOL!
-- 
Randy Yates
Digital Signal Labs
http://www.digitalsignallabs.com

On Thu, 09 Aug 2012 23:32:40 -0400, Randy Yates
<yates@digitalsignallabs.com> wrote:

>Robert Adams <robert.adams@analog.com> writes:
>> [...]
>> This is a nice visual that allows me to avoid math, since all the math
>> fell out of my head around 1980 as far as I can tell.
>
>"Fell out of my head?" ... LOL!
Hi Randy,
  In technical terms, isn't that called "overflow"?

[-Rick-]