Multisoliton complexes on a background

We obtain solutions of M coupled nonlinear Schrodinger equations that describe multisoliton complexes (MCs) on a background. We present explicit multiparameter families of solutions and numerical simulations, demonstrating specific features of MCs and their collisions. It is shown, in particular, that a MC on a background can have a complicated intensity profile due to a nonlinear superposition of pairs of bright and dark single solitons.