USRP TX/RX - IQ vs Real Sampling

Hi,
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I’m using the USRP and LFRX and LFTX daughtercards for an underwater
acoustics project.Â
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I am confused on how the IQ (complex) and real sampling works with the
USRP (I read a couple of papers and im still lost). If I wish to use
real sampling and I install two LFRX and two LFTX boards can I
effectively have 4 simultaneous transmitters and 4 simultaneous
receivers (I’m aware of the 16Mhz bandwidth limitation due to USB
transfer data rate)?Â
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I know the usrp_rx_cfile.py script saves data in complex form. For this
particular python script and an LFRX board, would the RX-A input
correspond to the I portion, and RX-B input to the Q portion?
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I’m still not sure what advantages there would be for using IQ sampling
for my particular application (I’m only interested in frequencies from
DC to 150 kHz). Does anyone know?
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Thanks,
Dan