I have a confusion about what does a two pass FIR (bandpass) filter with order 40 means?? Passband frequencies are [8 13]. Type 2 FIR is same as two pass??
I have check some previous literature which shows Linear-phase FIR filter can be divided into four basic types.
TYPE I symmetric length is odd
TYPE II symmetric length is even
TYPE III anti-symmetric length is odd
TYPE IV anti-symmetric length is even
But according to mathworks ([firtype]) : https://jp.mathworks.com/help/signal/ref/firtype.html
Type 1 - Symmetric factor with even degree
Type 2 - Symmetric factor with odd order
Type 3 - Asymmetric coefficient with even order
Type 4 - Asymmetric coefficient with odd order
kindly correct me if my understanding is wrong : Length = (Order-1)/ 2
If Type II is two-pass then the order of the filter will be even or Odd??