USRP as RF Relay with Adjustable Delay

[Mamanakis]

I would like to use a USRP as a RF relay with an adjustable delay. I want to sample and delay in memory and retransmit without streaming to the host; I want to inject delays of on the order of hundreds to thousand of nanoseconds and streaming to and from the host is too latent.

Is this something that is possible with off the shelf labview/uhd or would this require custom FPGA work? Can this be acheived with Labviews FPGA toolset?

Thanks.

[xavvvv]

Hi Mamanakis,

Unfortunately, you will need to stream the data to and from your computer for the processing. The USRP cannot retransmit on its own, which means the data will need to go to the host and get sent back effectively using twice the bus' latency. The delays you are looking for are not achievable using that route. Thus, you would need to configure an FPGA to accomplish this functionality (which unfortunately the FPGA is not open on current USRPs). Your best bet might be the FlexRIO or VST approach. Hope it helps!

[FarrisA]

Hello Mamanakis,

We announced today the USRP RIO that has a LabVIEW FPGA programmable Kintex 7 FPGA. The USRP RIO allows you to do the processing on the FPGA without the need to stream data to the host. And even if you need to stream data, the USRP RIO connects to the host PC with a low latency 800MB/s MXI x4 interface.

Please check out the following white paper for more information on the USRP RIO.

And the following webpage for the different USRP RIO models.

Cheers,

Farris A.

Product Manager, RF and Wireless Communication

National Instruments

[Mamanakis]

Are there plans to have USRP RIOS variants with the 120 MHz bandwidth daughterboards? Also, is it the XC7K325T or the XC7K410T under the hood?

Thanks.

[xavvvv]

Hi Mamanakis,

The FPGA on the USRP RIO is the Xilinx Kintex-7 FPGA, K7410T (so the XC7K410T). As far as future plans, we unfortunately do not discuss future road maps online. If you would like to talk to a National Instruments representative, feel free to contact them through http://www.ni.com/niglobal/