  The characteristic function of soliton phase jitter is found analytically
when the soliton is perturbed by amplifier noise. In additional to that from
amplitude jitter, the nonlinear phase noise due to frequency and timing jitter
is also analyzed. Because the nonlinear phase noise is not Gaussian
distributed, the overall phase jitter is also non-Gaussian. For a fixed mean
nonlinear phase shift, the contribution of nonlinear phase noise from frequency
and timing jitter decreases with distance and signal-to-noise ratio.
