Hi all,

I have some doubt in understanding working principle of usrp. I just want
to confirm my understanding:

1. I have AM modulated singnal x(t)cos(2*pi*fc*t) and i am receiving that
signal in antenna.

2. In Daughter board, this signal is multiplied by cos(2*pi*fc*t) and
sin(2*pi*fc*t) in two separate branches (assuming Direct conversion --
Baseband conversion)

3. Branch 1: x(t)cos(2*pi*fc*t) * cos(2*pi*fc*t) --> LPF --> x(t) --> FPGA

4. Branch 2: x(t)cos(2*pi*fc*t) * sin(2*pi*fc*t) --> LPF --> 0 (since cos
and sin are orthogonal) --> FPGA

5. Since Daughter board is doing direct conversion, no mixing in FPGA (i.e)
in DDC.

6. In PC, I will have I component as x(t) and Q component as 0 for AM
modulated signal.

Is my understanding correct?

Similarly if I take OFDM modulated signal -- xr(t)cos(2*pi*fc*t) -
xi(t)sin(2*pi*fc*t) -- output at Daughter board will be xr(t) at I
component and xi(t) at Q component. This will be send to PC. Is it correct?

Thanks
Senthil
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