A Volterra model for the high density optical disc

This paper presents a study aiming to define a nonlinear model, based on the Volterra series, of the high density optical disc read out process. Under the high density condition, because of the high linear density and reduced track pitch, the signal read out is not a linear process and suffers from crosstalk. To cope with such a problem the identification of a suitable nonlinear model is required. According to the Hopkins (1979) analysis, a physical model based on optical scalar theory was implemented. The results of this analysis have then been used to identify the kernels of a nonlinear model based on the Volterra series. The obtained results show that a second order bidimensional model is sufficient to accurately describe the read out process. The nonlinear Volterra model is a convenient starting point to devise and analyze nonlinear equalization and crosstalk cancellation techniques.