[Discuss-gnuradio] OFDM problem with USRP and GRC

Hi all

 

I am trying OFDM transmission and receive test.

I'm using Ubuntu 9.10, gnuradio version 3.3 and two USRP boards with basic TX and RX and I am using GRC.

 

In the GRC I make simple test signal flow with usrp

 

Tx : File source -> OFDM mod -> USRP sink

Rx : USRP source-> OFDM demod ->file sink

 

As a my test I could not show not only constellation but also any other signal(scope and file data)

But I could show receive spectrum using fftsink with USRP

However I created simple example like follow, it operate well.

 

File source-> OFDM mod-> OFDM demod ->file sink

 

In order to test USRP part I tested gpsk example in the gnuradio-examples

It operate well. I could show constellation.

 

How can I operate well OFDMmod / demod examples?

 

Additionally I wanna confirm constellation of OFDM demod data.

 

But GRC block of the OFDM demod are encapsulate. So To confirm OFDM démod constellation, I guess that I sholul split OFDM démod block.

Am I correct?

 

Can you have a some hint?

 

Sohn