Hi, In the document of FIR Complier v3.2, it talks about coefficient padding. I have several questions about that topic. It gives an example:
MAC0 l m n p MAC1 h i j k MAC2 d e f g MAC3 0 a b c
It said that this kind of 0 padding will cause phase shift with the normal non-symmetric structure.
It then gave two examples in Figure 28 using interpolation.
Interpolate by 2
a, c, e, g, h, f, d, b----- |-------- b, d, f, h, g, e, c, a-----
For this example, I don't know why they use interpolate 2 sturcture. The simple "a, b, c, d, e, f, g, h" has the same complexity.
For the second example, how to use the coefficients in the FIR structure?
Even Sym: a+b, c+d, e+f, g+h, h+g, f+e, d+c, b+a. Even Sym: b-a, d-c, f-e, h-g, g-h, e-f, c-d, a-b. (negative sym)
Could you explain it to me? Thanks a lot.