We introduce higher level $q$-oscillator representations for the quantum affine (super)algebras of type $C_n^{ (1)},C^{ (2)}(n+1)$ and $B^{ (1)}(0,n)$. These representations are constructed by applying the fusion procedure to the level one $q$-oscillator representations which were obtained through the studies of the tetrahedron equation. We prove that these higher level $q$-oscillator representations are irreducible. For type $C_n^{ (1)}$ and $C^{ (2)}(n+1)$, we compute their characters explicitly in terms of Schur polynomials.
Categories: math.QA