video streaming using OFDM

[DOHAAACB19619]

Hi,

i have a problem in streaming a video using OFDM example implemented on labview communication.

that i send a video to labview comm through UDP,the steps that must be done are:

(1)the video passes through the transmitter of the ofdm and then to the receiver.

(2)after processing we will receive this video also using the UDP.

-the problem is that i think that there is a problem that occurs to the data in the OFDM (TX,Rx),the received video showing like images interfered with each other .

here an attachment of the code of the OFDM (TX,Rx) without any change ,and the new code with changes suitable for video streaming.

i hope someone help me solving this problem,

thanks a lot,

[Danny_Kaps]

Hi DOHAACB19619,

There is a separate forum for LabVIEW Communications, where users may be more equipped to help with your question. I recommend making a new post here: http://forums.ni.com/t5/LabVIEW-Communications-System/bd-p/540

That being said, for your new post, I think answers to the following questions would be really useful to help the community lead you toward the answer quickly:

1. Could you confirm that you're starting from the SISO TDD OFDM on NI USRP RIO example in LabVIEW Comms 2.0? If not, which example and version of Comms are you using?

2. Which USRP RIO are you using?

3. Could you provide screenshots of the interfered video signals?

4. Have you tested your modulation scheme with a simpler use case (not video but perhaps an array of values)? Do we still see degradation?

5. Which loopback setting are you using? 

6. What is the overall application? Are you trying to test your OFDM scheme with video, just stream video via USRP, etc? Understanding the end goal will help the community design test cases and provide application level suggestions.

Best,

Daniel K.

Applications Engineer | National Instruments

[DOHAAACB19619]

Hi  fiendfyre ,

first  I am grateful for your concern and your help, thank you very much,

(1) yes I am starting from the SISO TDD OFDM on NI USRP RIO example in LabVIEW Comms 2.0 ,but the problem is that this example is suitable only for one USRP transmit and receive from only one RIO, in fact I want to transmit on one USRP-RIO and receive from other one in another location.

(2) the size of the sent video is about [1472] byte ,when this video of this size entered to the OFDM (TX,Rx) the data is corrupted i dont know the reason but i think that this transmitter and the receiver is not suitable for this size.

(3) yes I tested the modulation scheme with a simpler use case.

(a) I used labview normal to send a packet that consist of  text of a string of length [367] using UDP to the OFDM example the result is that :received string length [375] and it  is exactly equle to the transmitted one but  at the end of the text there are some strange additional strings[] the attached picture showing these strings. 

(b) sending a packet that consist of  text of a string of length [662] using UDP to the OFDM example the result is that :received text contain only about half of the data of length [375] and the rest are missed.

(c)sending a packet that consist of  text of a string of length [375] using UDP to the OFDM example the result is that :received string  is exactly equle the transmitted one without no missed or additional strings.

-so i think the OFDM[TX,RX] are designed to accommodate only data of length [375] .

-what is your suggestion?

thank you again, 

[JohnSmith7777]

Hi,

        When I open the OFDM(tx,rx).7z archive, I am missing a lot of modules, such as M-QAM modulation, can you tell me where to find this example? Or you can send me a complete file archive. I would be very grateful !