S 7.2 Selection of Filter Type For FIR digital filter design,the FIR transfer function is a polynomial in z1 with real coefficients: H(z)=∑hin]z-" n=0 For reduced computational complexity,degree N of H(z)must be as small as possible If a linear phase is desired,the filter coefficients must satisfy the constraint: h[n=±hN-n§7.2 Selection of Filter Type For reduced computational complexity, degree N of H(z) must be as small as possible • If a linear phase is desired, the filter coefficients must satisfy the constraint: h[n] = ± h[N-n] = ∑ = − N n n H z h n z 0 ( ) [ ] • For FIR digital filter design, the FIR transfer function is a polynomial in z-1 with real coefficients: