[Discuss-gnuradio] How to use the rx_decim and interp.

[srinivas naga vutukuri]

Hi,

Am trying to send IQ samples of float from one usrp2 to another usrp2. 
As an ex: am taken the data of Sinusoidal generated from MATLAB, and 
pumping into the 1st one using tx_samples and receiving into the 2nd 
usrp2, and collecting into output file using -I option to the 
rx_streaming_samples. I have just changed in the rx_streaming_samples.cc 
(Actually i saw the output file creating like binary data), to convert 
the host_items[i] complex into the real, imag and writing into the 
output file, and trying to plot. I observed the values, there is no near 
matching. And also i am using attenuators to test ideally rather 
connecting the antennas on both usrp2.

How to use the rx_decim on rx side and interp on tx side? What is the 
equation of sampling rate, and how the both rx_decim and interp are related?


And also am trying to understand the ADC/DAC rates. I just put the 
usrp2::impl::adc_rate(), usrp2::impl::dac_rate() in the constructor 
usrp2::impl::impl() to see, i got both values printed as 1, (assuming 1 
MHz or 1 MS/s). But from gnuradio.org site, i saw that ADCs (100 MS/s) 
and DAC (400 MS/s). So can able to set these values also?


Please help me in understanding these, and also to make my trial work 
(ie., sending IQ samples, lets say 10 MS/s rate).


best regards,
srinivas.