MATLAB: Query regarding n in the equation

filter

I have implemented this equation in matlab
In equation
h[n] = (2/L) cos ( 2 π fb n / fs ), 0≤ n < L
where L is filter length, fb center frequency of the filter (frequency to be filtered), n is number of filter points, and fs is sampling frequency on which filter is implemented.
What we mean by Filter Points (n). Can u kindly explain What is difference between L and n
And i hope that Filter length means order of Filter. Am i right??

Best Answer

  • L here is the length of the impulse response. n is the term in the sequence. The order of the filter is the length-1. That is because the first term in the z-transform is z^{0} for a causal filter. That means for length L, the highest term is z^{-(L-1)}. So the filter is order L-1.