Forward Error Correction and ARQ with 2 NI-USRP 2920 devices

[florianschweitzer]

Hello all,

I am currently working on a project where I need to transmit data (e.g. an image) from 1 USRP 2920 device to another one (which is also a USRP 2920 device).

Until now, I can transmit and receive images, but in the next step I want to add forward error correction (FER) and Automatic Repeat Request (ARQ) to the transmission to achieve higher transmission quality.

Especially for ARQ I need a feedback channel, so that the receiver can inform the transmitter about the status of the received data (ACK or NACK).

Does anybody have any idea how I can implement such a feedback channel in LabView with the above mentioned devices?

Is it possible to realize this feedback channel with the MIMO cable which connects the 2 USRP devices?

Thanks for your reply.

Kind regards,

Florian Schweitzer

[aabrol]

Hi Florian and NI Professionals,

I am in a similar situation in my Image TX/RX via USRPs project. I am just not able to understand how to synchrozize tx and rx operations.

Florian wrote here that you could transmit and receive images. In your VI, how do you gain the knowledge of start of frame? Did you synchronize the tx and rx? I believe what you transmit is scaled down (amplitude/voltage varies, numbers are not received as it is) and we dont have a knowledge of the scaling factor.

I am sure there would be some sort of method to overcome this limitation.

In short, I am wondering how to receive on a USRP what we transmit via another USRP "as it is"?

Anees