Primitive Polynomial (Generate Bits VI)

[josephkirmani]

In the attached VI, I am trying to generate bits using PN sequence and primitive polynomial. I am having problem in primitive polynomial. If I have a primitive polynomial (x^4 + x + 1) can any body guide me how to run it ? I tried many different ways but receive error.

Thanks 

JK

[Bob_Schor]

I, for one, do not have the Modulation Toolkit installed, so I can't examine the MT Generate Bits VI, nor look at its Help message.  However, if you do a Web search for "MT Generate Bits", you will find other postings that discuss how to use this VI.

BS

[josephkirmani]

I searched alot but did not find any example where Primitive Polynomial is used. Please share a link if you find any relevant example.

[josephkirmani]

Screen shot of the error. Can anybody guide me how to fix this error.

[Bob_Schor]

Sorry, as I explained, I don't seem to have the proper Toolbox installed.  I also don't really understand what you are doing.

I (or other readers) may be able to provide additional help if you explain a bit more what you are trying to accomplish.  Tell a complete story, with lots of details.  Be sure to say what version of LabVIEW you are using, and where the special Functions you talk about can be found -- that would at least enable some of us who are curious to poke around and see what we can figure out.  In particular, what are you trying to do with the primitive polynomial?  [I rather thought that it played a "behind-the-scenes" role ...].

BS

[Bob_Schor]

Assuming you are doing RF Communications, I found a link that gets you into some NI Tutorials that might help.  Start here and wander.

BS

[josephkirmani]

I just simply want to know If I change PN sequence in to primitive polynomial then why VI gives error. I do not understand the reason of error and the explaination which is giving for solving the error. I just want you or someone to guide me what mistake I am making. 

Thanks

JK

[josephkirmani · Accepted solution]

I fixed it my self.

Thanks

[Bob_Schor]

Instead of marking as a solution "I fixed it myself", why not write a little essay on the nature of the problem, and what the fix was?  A "solution" should be something that would be helpful to someone else.  As it is, noone reading this thread has any understanding of the problem (you didn't answer my request for more information to help understand the problem), and you have provided no information as to the solution.  Please consider remedying this.

Bob Schor

[josephkirmani]

Since my primitive polynomial (1 + x  + x^4) which is in terms of bits 11001. As the labview help says it should be N+1 elements and N is define as x^N, which is 4 here so I have 5 elements which fullfills its requirement. But if you look at the error screen shot above it was related to PN sequence order. So when I open generate bits VI I found that in this vi first it measure array size and then subtract 1 from array. Since there are only five elements in the above polynomial so If I sub 1 it becomes 4  and generates error. So what I did I add one additional bit and make it 110010 and it works. I am not sure what I did was right or not but that's how I fixed it. If you do not mind please I request you to install Modulation toolkit and try to run this yourself and let me know what i did was right or not. 

Please find screen shot of the Generate bits VI.