I have two USRP N210 modules and I want to do simple QPSK transmission from one module and reception using the other. I took the Simulink examples sdruqpsktx and sdruqpskrx, copy pasted them into a single simulink model, entered the correct ip addresses and center frequency of the USRP modules and ran the model. I did not change any of the parameters in any parts of the models. I receive the transmitted data for some time but then I start receiving garbage. What can I be doing wrong?
A few things I must mention: 1. I have connected both the USRP modules and my Computer to a Gigabit Ethernet switch. The network card in my Computer does not support Gigabit Ethernet so I cannot connect the USRP modules directly to my Computer. 2. I have already used the frequency calibration examples (sdrufreqcalibtx and sdrufreqcalibrx) and the frequency offset is shown to be -588.3. However adding this to the receiver center frequency does not solve the problem, the received data still turns to garbage after a few seconds. 3. I am using the correct RF ports for TX/RX and the RF daughter card is working fine. 4. I am using MATLAB R2014a.