Hi all,
I want to sample first 250KHz on the channel.
I am using the (sampling_with_lowpass.JPG) setup to extract quadrature samples.
I have LFRX card where i just use the RX-B pin to extract complex samples from the channel.
My question is (question.JPG) how are the two setups different, assuming the connections are correctly made.
a) I set the sample rate= 250KHz, and center freq=125KHz.
b) I set the sample rate=500KHz, and center freq= 0 KHz (I hope the card is fine with setting center freq=0)
Q1 ) I understand that the sampling rate will be different, but I should be getting the samples from same bandwidth ? 0-250KHz
Q2 ) in b), how do i interpret the negative frequencies in complex FFT.
( I understand these are frequency in opposite direction acc to books, but not sure if they make sense here, and hence I am doing way a) )
Apologies, I am CS student so I might not be very clear with my EE fundamentals.
Thanks,
Abhinav