Hello All, I am trying to build OFDM_MIMO (2 x 2). I have used the blocks from OFDM example folders and joined tx & rx together and transmitting/receiving over USRP B210. My aim is to get a channel state information (CSI). For that I have connected TAG DEBUG with OFDM CHANNEL ESTIMATION block which gives me the complex values. As there are 2 RX antennas (2 separate channels) therefore I have 2 CSI values (over 2 TAG DEBUG block). My question therefore is how can I separate these values for each transmit antennas. So that I can get the CSI values for each of them: Tx1 --> Rx1 Tx 2 --> Rx1 Tx1 --> Rx2 Tx 2 --> Rx2 Please let me know if I have made myself clear. Thanks, Ayaz

On 06/21/2018 01:57 PM, Ayaz Mahmud via USRP-users wrote: > > Hello All, > > I am trying to build OFDM_MIMO (2 x 2). I have used the blocks from > OFDM example folders and joined tx & rx together and > transmitting/receiving over USRP B210. > > My aim is to get a channel state information (CSI). For that I have > connected TAG DEBUG with OFDM CHANNEL ESTIMATION block which gives me > the complex values. > > As there are 2 RX antennas (2 separate channels) therefore I have 2 > CSI values (over 2 TAG DEBUG block). My question therefore is how can > I separate these values for each transmit antennas. So that I can get > the CSI values for each of them: > > Tx1 à Rx1 > > Tx 2 à Rx1 > > Tx1 à Rx2 > > Tx 2 à Rx2 > > Please let me know if I have made myself clear. > > Thanks, > > Ayaz > > My guess would be "write a little bit of code". If you aren't familiar with the idioms of the programming language that you're using, then asking *here* for help with those idioms and methods and techniques is not really appropriate. If you aren't reasonably familiar with the programming environment used by the OFDM examples, then perhaps starting with those as your "introduction" might not be such a good idea. Just forming an opinion from what I see from the outside. The truth may be quite different, I don't know.

On 06/21/2018 10:57 AM, Ayaz Mahmud via USRP-users wrote: > Hello All, > >   > > I am trying to build OFDM_MIMO (2 x 2). I have used the blocks from OFDM > example folders and joined tx & rx together and transmitting/receiving > over USRP B210. > >   > > My aim is to get a channel state information (CSI). For that I have > connected TAG DEBUG with OFDM CHANNEL ESTIMATION block which gives me > the complex values. > >   > > As there are 2 RX antennas (2 separate channels) therefore I have 2 CSI > values (over 2 TAG DEBUG block). My question therefore is how can I > separate these values for each transmit antennas. So that I can get the > CSI values for each of them: > >   > > Tx1 à Rx1 > > Tx 2 à Rx1 > > Tx1 à Rx2 > > Tx 2 à Rx2 So, you're asking about the actual MIMO processing, not how to use USRPs, right? How much background do you have? And have you been following the gr-mimo GSoC project? -- M