Hello,

If you are using the standard LMS filter implementation with MATLAB, I think you can do it at the time you want to obtain the output signal Y after applying your filter H to your input signal X from your noise (mixed)  signal D:

[Y,ERR,WTS] = step(H,X,D,MU)

Where MU is configurable by declaring your filter H adequately:

H = dsp.LMSFilter(..., "StepSizeSource", Input port, ...)

http://www.mathworks.com/help/dsp/ref/dsp.lmsfilter-class.html?s_tid=gn_loc_drop

I hope this information is useful.

Regards,

Bruno

You may refer to the link for direct simulation

http://in.mathworks.com/help/comm/ref/variablesteplmslinearequalizer.html

I can not use the toolbox functions. I have to write them in manual way. Means to write the equations in matlab to perform same as defined function.

If anyone can write a matlab program using variable step size algorithm that would be useful.