7.1 Linear-phase FIR transfer function Type 1 linear-phase: To T is a constant Type 2 linear-phase (o=8o-to r is a constant, 0 is a initial phase aa unify representation dElo7.1 Linear-phase FIR transfer function Type 1 linear-phase:     ( ) = − is a constant Type 2 linear-phase:  A unify representation: ( ) 0 0       = − is a constant, is a initial phase d ( ) d     − =