Identifiability of nonlinear channels

In this contribution, the problem of identifiability of nonlinear channel is addressed. We use the algebraic approach, that we have presented in preceding communication (S. E. Asmi et al., 2001), to analyse the question of perfect equalization of multi-user channels. We give a new definition of identifiability of nonlinear channel. This definition clarifies the fundamental link between the problem of observability of input-output system and the channel parameters identification. We provide a test of that definition in terms of ranks of Jacobian matrices.