12-20-2019 05:37 AM
Hello everyone,
I am trying to program the FPGA in the usrp 2954R so that I can apply some channel effect on the signal coming from the Rx port of the USRP.
For this purpose, I want to know if the received data is in baseband or in passband.
I attached the usrp receiver code below to make my question clearer.
Is the data indicator in the photo indicates the complex received signal in baseband or passpand ??
What if I want to stream it to the FPGA ? should directly use a FIFO inside the while loop ?
Many thanks,
Ali
05-18-2020 04:17 AM
HI,
The NI USRP connects to a host PC to act as a software-defined radio. Incoming signals attached to
the standard SMA connector are mixed down using a direct-conversion receiver (DCR) to baseband I/Q
components, which are sampled by a 2-channel, 100 MS/s, 14-bit analog-to-digital converter (ADC).
The digitized I/Q data follows parallel paths through a digital downconversion (DDC) process that
mixes, filters, and decimates the input 100 MS/s signal to a user-specified rate. The downconverted
samples, when represented as 32-bit numbers (16 bits each for I and Q), are passed to the host
computer at up to 20 MS/s over a standard Gigabit Ethernet connection.
For transmission, baseband I/Q signal samples are synthesized by the host computer and fed to the
USRP-2920 at up to 20 MS/s over Gigabit Ethernet when represented with 32-bits (16-bits each for the
I and Q components).