Re: [Discuss-gnuradio] USRP Tx Rate Conversion

[Eric Blossom]

On Thu, Apr 17, 2008 at 11:26:06AM -0400, Brian Padalino wrote:
> On Thu, Apr 17, 2008 at 11:11 AM, Wireless Monster
> <address@hidden> wrote:
> > Brian, Dan,
> >
> > It is working now. Thanks again for your help.
> >
> > One more basic "signal processing question" ... knowing that the input and
> > output are complex (GMSK modulated signal), should I use complex or real
> > coefficients for the resampler filter  (rational_resampler_ccc, vs.
> > rational_resampler_ccf) ?
> 
> I wouldn't use a ccf.  I'd either use an fff on each the real and
> imaginary portions of the signal, or I'd use a ccc on the combined
> signal, but that's just my own personal opinion.

ccf is equivalent to fff on each of the real and imaginary.

(a+bj) * (c+dj) = (ac - bd) + (ad + bc)j
If d is zero -> ac + bcj

Eric