[Discuss-gnuradio] Questions on DDC's

[Anastasopoulos Achilleas]

Guys, I remember someone gave me an answer to
a similar question in the past regarding the Digital upconverter
in the TX path that is implemented inside the ADC chip.

I have a similar question for the DDC in the RX path which is implemented
in the FPGA:

On the receiver path, the DDCs perform complex or real multiplication?
My guess is the latter, ie, if the input signal (from the MUX) is
si(t) in the I input of the DDC and sq(t) in the Q input of the DDC,
and if the CORDIC frequency is fc, then the output complex
signal is
[si(t)+j sq(t)] exp(j 2 pi fc + phi)

Is this right?

Thanks
Achilleas