[Discuss-gnuradio] Enable/Disable TX ports in B210 in 2x2 setup

Hi All,

 

So my ultimate goal is to get the CSI (Channel State Information) between 2 Tx antenna (1^st B210) and 2 Rx antenna(2^nd B210). So that each antenna at Rx will have 2 CSI measurement.

 

Attached is my picture of the flowgraph.

 

To build this scenario, I have used the "Tx_OFDM" and "Rx_OFDM" from Gnuradio examples. I am using a text file to be transmitted. Exact same blocks are used twice (to make 2 channels) and fed into an USRP sink.

 

At receiver side USRP source is used with other blocks to decode. & Tag Debug box is added to read the CSI at console.

 

This setup work fine. But I am seeing only 1 CSI measurement at each Rx antenna. This is because I am transmitting the same signal at same time from 2 Tx antennas, so it is arriving at the same time at Rx thereby the 2 CSI values are accumulated ( I am guessing) !

 

I have tried to add a delay in one tx antenna, but the result was same.

Now I am trying to transmit from 1 antenna at a time. So 1^st Tx antenna signals will be received at both Rx antenna thereby give 2 CSI measurement. It will then stop transmitting and the 2^nd Tx antenna will start transmitting which will also give CSI from 2 Rx antenna.

 

So I wanted to know if this enabling/disabling of antenna (TX/RX) port is possible or not.

If it is not possible, what are the possible workarounds?

 

 

Thanks,

Ayaz