Data lost when transmitting pictures and video based on digital/OFDM/rx_ofdm.grc and tx_ofdm.grc

[zhang yue]

Hi, there,

 

I am new to OFDM. My GNU Radio version is 3.8.4

I am trying to transmit data by modifying the .grc example.

I change the tx_ofdm original random_source block to file_source and add a usrp_sink after the tag gate, I also tune the multiply const to 2m to make sure the signal won’t out of the usrp signal range.

In the rx_ofdm, I disable blocks before Schmidl & Cox OFDM synch and add usrp_source before it. And add file_sink after the stream_crc32.

For the hardware, I use two N210 with LFRX and LFTX, and I use a cable directly connecting them instead of the Antenna.  

At the beginning of my experiment, I tried to transmit a text file, and it works fine. But when I am trying to test the picture, each time the picture I received has lost the very bottom part. After that, I tried an mp4 video. The size of the received video is 24000Bytes smaller than the original one.  And can’t open it via the any media software.

Can someone help me why this happened and how to fix it?

 

Thanks,

Yue