Understanding FPGA FXP LMS.vi code

[charansai]

Hello everyone,

I am working on Active Noise Cancellation project. I need to implement fixed point LMS code on FPGA target of myRIO 1900. I know , I can generate this using FPGA Target > IP Generator. I could do that, but I have to modify that code a litlle bit, as I will directly get the error e signal from microphone and there is no desired signal davailable.

I did some decoding and understood a bit of how it is working, but still could not understand some essential part of it! 

Below I will attach, the FXP LMS vi . There are also two subVIs needed which I cannot include here but I can add pictures of it if needed.

I could not understand, how this algorithm performs the Estimated signal step viz. [ y(n) = x_temp(n) vector * w(n) vector '  ; ]. I marked the section of the code where I am facing some problem in the attached picture. The algorithm does not show any clue how it is performing these vector operations.

I could not also understand, some logic with numbers that he has chosen like 8, 3 ,7 ,9 etc. 

 

Further clarifications on my understanding will be provided .

 

Any help in this problem will be appreciated.

 

PS: I could implement using memory blocks as basic array elements, like intialzing both x and w vectors. But eventually, I have to read and write several times, which is killing time.

 

FXP LMS.vi

Edited November 26, 2015 by charansai