  We propose discrete-time polarization mode dispersion (PMD) models that are
compatible with the emerging coherent receiver techniques, and statistical
sampling schemes for the model parameters. These models use multiple-input
multiple-output (MIMO) finite impulse response (FIR) filters that are lossless
and therefore lend themselves as perfect candidates for emulation of fiber
channels suffering from PMD without polarization dependent loss (PDL). The
concatenated composition of these filters resembles the continuous time lumped
model of PMD channels and offers a flexible emulator and compensator structure
in terms of computational complexity which constitutes the main bottleneck for
real-time DSP applications.
