Channel Estimation using the SISO TDD OFDM Video Streaming on NI USRP RIO

[Kazekage]

Hello all

I am trying to modify the example "SISO TDD OFDM Video Streaming on NI USRP RIO" that comes with the LabVIEW Communications Systems design

suite. What I want to do is to perform channel estimation from the subcarriers so that I process the estimated channel further later on.

Can this example be modified for this task?

If yes, can you please advise on the steps?

Many thanks.

Kaze

[Ben_Co]

Hi Kazekage,

It should be possible to implement this, however to what extent may be limited. In LabVIEW Communications on the FPGA side, there is an 3GPP LTE Channel Estimator that you could try and incorporate. You can find the description of this function here: http://www.ni.com/documentation/en/labview-comms/1.0/cdl-node-ref/3gpp-lte-channel-estimator/. If you don't have the license for the Xilinx IP however, you will not be able to utilize this code, and will have to implement your own Channel Estimator. 

My understanding is that the Channel Estimator comes after the OFDM Demod, and before the Equalizer, so you could try inserting the channel estimator between FIFO that outputs the demodulated OFDM and the ZF Equalizer in the "transceiver_top.gvi". That being said, depending on how and where you want to implement this, that may vary. 

I will look into this a bit more and see if there is a better recommended place to insert that code. 

Thanks,

Ben C. 

Applications Engineer

[Kazekage-Sama]

Dear BeenCoughin,

Thank you for your reply. Could you please let me know where can I find the 3GPP LTE Channel Estimator block? I searched for it and could not find it.

Many thanks.

[Kazekage-Sama]

Is it possible to use Xilinx IPs in the LabVIEW Comm. suite? If yes, can you please illustrate or provide a reference document/link?

Many thanks

Kaze

[Ben_Co]

Hi Kazekage,

You can find it in an FPGA gvi under the Xilinx IP on the palette on the lefthand side, see my picture below. With regards to utilizing the functionality of the Xilinx IP, I would recommend contacting Xilinx on the low-level control of those IP nodes. 

Regards,

Ben C.

Applications Engineer

[Kazekage-Sama]

Hello Ben,

Thank you for your reply.

Now I have also installed a licensed Xilinx to my PC. I saw that in one of the examples there is an Xilinx FIR IP which is used normaly (see attached). However, when I drag the Channel Estimator, it asks for configuration and when I try to configure it, it shows that it is locked and can not be configured or used (see below). Any suggestions please?

Thanks.

[Ben_Co]

Hi Kazekage,

Do you have a license to use the Xilinix IP? If you do not, you need to follow the steps here: http://digital.ni.com/public.nsf/allkb/1BC64382AF80934C86257DFC00566EB5. The Xilinix IP is a separate license from the LabVIEW Communications one. 

Thanks,

Ben C.

Applications Engineer