Does the FPGA code for BASIC_RX support a Hilbert transform to convert
one of the real inputs into a complex stream?
–
Marcus L.
Principal Investigator, Shirleys Bay Radio Astronomy Consortium
On Thu, 2009-04-16 at 14:22 -0400, Marcus D. Leech wrote:
Does the FPGA code for BASIC_RX support a Hilbert transform to convert
one of the real inputs into a complex stream?
No, but if your signal of interest has a passband above DC, when you
“tune” the BasicRX, the complex mixer in the FPGA will still
down-convert it to a complex baseband I/Q signal.
Johnathan
Johnathan C. wrote:
Johnathan
Ah, fabulous. So if I have a 10.7MHz IF coming out of a receiver in
real mode, I can just “tune” the BASIC_RX
to 10.7, and it’ll as-if-by-magic become a complex signal of +/-5Mhz?
Sweet.
–
Marcus L.
Principal Investigator, Shirleys Bay Radio Astronomy Consortium
On Thu, Apr 16, 2009 at 11:51 AM, Marcus D. Leech [email protected]
wrote:
Ah, fabulous. So if I have a 10.7MHz IF coming out of a receiver in
real mode, I can just “tune” the BASIC_RX
to 10.7, and it’ll as-if-by-magic become a complex signal of +/-5Mhz?
Close. You didn’t mention USRP1 or 2, so I’m assuming USRP1, and
you’ll get a baseband signal of a maximum +/-4MHz with decimation of
8.
It’s not magic, it’s math 
Johnathan
Johnathan C. wrote:
On Thu, Apr 16, 2009 at 11:51 AM, Marcus D. Leech [email protected] wrote:
Close. You didn’t mention USRP1 or 2, so I’m assuming USRP1, and
you’ll get a baseband signal of a maximum +/-4MHz with decimation of
8.
Yes, USRP1.
It’s not magic, it’s math
It’s so much more fun to think of it as magic, but yes, it’s math.
Coupla synthetic LOs, coupla multiplies, voila, a complex mixer.
I’ll actually be using it at +/- 3.2MHz (decim=10).
–
Marcus L.
Principal Investigator, Shirleys Bay Radio Astronomy Consortium