Hi guys, Jean-Benoît Larouche here field application engineer at Nutaq and the goal of my video today is to show you a cool demo that I just made which is basically taking the OFDM reference design and move it into a cognitive OFDM reference design.
So first of all, let’s take a look at our hardware setup for the demonstration.
So here we have my PicoSDR system with two antennas in receive and two antennas in transmit which implement our OFDM transmission. So the video is sent over the air and the received video file is sent to the computer for scoping.
Here we have a spectrum analyzer which shows the transmitted spectrum and on the bottom the signal generator will generate interference. So let’s see how our system is affected by interference without being cognitive.
So we can see that in the presence of interference the actual reception of the video file was impossible. But thanks to the OFDM transmission in MIMO scheme we were able to recuperate from that and the video is still running. So now, let’s configure our system in cognitive mode and see how we can get a better result for the reception in the presence of interference.
So now we have just configured our system in cognitive mode, which means we are actually listening to the channel before transmitting in it. And if the noise level or the interference level is higher than the actual user defined threshold, we are switching to a transmitting frequencies and receive frequencies. So let’s see how it affects our transmission now.
So now we can see that we are listening to the channel before transmitting in it and so we are changing frequency in real time to actually reduce the number of error and get a better quality of transmission. A very cool thing about this is that all this dynamic reconfigurations are done in the FPGA so saving a lot of latency which enables to reconfigure the actual radios in real time on a packet per packet basis. And also, since we are in a MIMO system configuration here, both FMC radio can be configured in parallel at the same time for better transmission and reception coherence.
So thanks for watching guys and don’t forget to look at the upcoming blog regarding this demonstration, and see you later.