USRP 2930 GPS disciplined clock sync and continuous transmission

[aster_yeyo]

Hello all,

I want to transmit a continuous wave signal with gps synchronized clock on USRP 2930. I have 2 of them. I want to send and receive the IQ data which is synchronized with the gps clock. On the receiving side I want to know the exact time when it was sent. I am using examples of labview which are:

niUSRP EX Tx/Rx with GPS.vi

In this example. This example send the data on a particular time entered by user. I want to send it continuously using GPS sync. On the receving side. I want to know the exact time it was sent. 

If any one can provide such example which is better than this on. I would be happy or any idea to implement on this example.

[Shalini.M]

Hi, 

Have you seen the RF Record and Playback with NI USRP Example? That implements the continuous functionality you mentioned.

[aster_yeyo]

I believe my application is different from the example you have mentioned. 

[Shalini.M]

The example should be a good starting point for continuously acquiring and then modifying to achieve your exact desired functionality.

Is there something in particular that is missing that you have questions on how to implement?

[aster_yeyo]

Yes I want to synchronized two usrps with gps clock and sent and receive data with this system. and Transmission system should be continuous. Do you know any such example

[Shalini.M]

I don't know of an example that accomplishes exactly what you are hoping to accomplish but I think you should be able to modify either your existing VI to accomplish continuous acquisition or modify the record and playback example and incorporate GPS synchronization. 
The 2nd option might be easier because that would involve changing the clock sources to point to the GPS. 
Section 6 of the following tutorial provides more information on that: http://www.ni.com/tutorial/14705/en/

[aster_yeyo]

Okay i got a continuous aquisition. Now i want to check whether two usrps are sync or not. And when i transmit a sine wave same as given in niusrp continuous example it recieve same  bit when i change the signal sources to square wave i dont receive the same signal. I dont knoe why the receive signal has envelopes. I think it should be same as transmitted. Do you know whats the issue

[Shalini.M]

Could you attach screenshots of what you are seeing or the code itself? Are you getting any errors?