Question regarding USRP 2920 communication

[Michael_Ru]

Dear NI community,

in my bachelor thesis I am using two USRP-2920 radios to build a transceiver and I encountered some trouble by processing the signal from transmitter to receiver. I am new to USRP and SDR. My scenario should be as follows:

1. The transmitter has to send gauss impulse pairs (DME signal) to the receiver (screenshot attached below).

2. After successfuly receiving a pulse pair the receiver has to wait 50us and then send the received signal back to my transmitter.

I can't really imagine how to get the radios to send and receive at the same time... I already tried it by using the VIs in this topic (https://forums.ni.com/t5/USRP-Software-Radio/Can-a-single-USRP-2920-tansmit-Tx-and-receive-Rx-at-the...) but each USRP sends his own signal and isn't really calculating, modulationg etc. the signal coming from a corresponding transmitter.

I connected my USRPs as it is shown in a screenshot attached below.

Can someone please help or give me some advices on how to implement this communication scenario?

[EzerB · Accepted solution]

Hi Michael_Ru,

please look at the block diagram of the USRP on http://www.ni.com/datasheet/pdf/en/ds-355 (p. 2). As mentioned there, each USRP-2920 provides an independent transmit and receive channel so that it is capable of full duplex, i.e. sending and receiveing at the same time. So you should connect Tx1 of each USRP with Rx2  of the other USRP to achieve a full duplex configuration. Please note that while working properly with cables, this configuration may be noisy if you use antennas, since the antennas are too close to each other.

I hope those hints will help you go ahead in your thesis.

Best of luck 🙂

Best,

Ezer Bennour

Applications Engineer

National Instruments

[Alias@az1]

Dear Ni Community,

I'm using two USRPs one for the transmission and other for the receiving the problem that I'm facing is that signal is not received accurately at the receiver , the noise is actually been received. Kindly help in resolving this problem.