  There is a fundamental limit on the capacity of fibre optical communication
system (Shannon Limit). This limit can be potentially overcome via using
Nonlinear Frequency Division Multiplexing. Dealing with noises in these systems
is one of the most critical parts in implementing a practical system.
  In this paper, we discover and characterize the correlations among the NFT
channels. It is demonstrated that the correlation is universal (i.e.,
independent of types of system noises) and can be exploited to maximize
transmission throughput. We propose and experimentally confirm a noise model
showing that end-to-end noise can be modeled as the accumulation of noise
associated with each segment of optical communication which can be dealt with
independently. Also, each point noise can be further decomposed into different
components, some of which are more significant (and even dominating) than
others. Hence, one can further approximate and simplify the noise model by
focusing on the significant component.
