  We investigate the potential of adaptive equalization techniques to mitigate
inter-channel nonlinear interference noise (NLIN). We derive a lower bound on
the mutual information of a system using adaptive equalization, showing that
the channel estimation error determines the equalizer's performance. We develop
an adaptive equalization scheme which uses the statistics of the NLIN to obtain
optimal detection, based on Kalman filtering and maximum likelihood sequence
estimation (MLSE). This scheme outperforms commonly used equalizers and
significantly increases performance.
