dear all

     As we know,  ISI is caused by cable's group delay distortion and amplitude attenuation. the groupdelay distortion represents the channel’s nonlinear phase distortion,which results in post-cursor signal distortions and adds jitters to the received data eyes.The received
data eyes are no longer peaked at bit centres,and the eye diagrams are no longer symmetric.
     I have a question , for a given cable ,and we have its eye diagram. how can we kown how much jitter caused by  cable's group delay distortion , and how much jitter caused by  cable's amplitude attenuation. which way can we use to simulate through cable's s param, tran/ac or some others...  

BRS
andyseu