Methods for partial response maximum-likelihood (PRML) detection and crosstalk cancellation are discussed. In accordance with the demand for increased recording density, a 20 Gbyte digital versatile disk (DVD) ROM channel is considered. The channel is modeled to be close to a real optical channel using DIFFRACT™. After comparing the spectral characteristics of various PR polynomials, P(D) = 1 + D+ D2 + D3 is proposed as a target PR. The performance of the system is illustrated under the condition that the readout signal is degraded by crosstalk, radial tilt, and nonlinear distortions in optics. Finally, we present the multispot detection technique for crosstalk cancellation. The simulation results show that if no radial tilt is present, crosstalk is fully cancelled.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics