Representations of non quasi-split unramified U(4) over a p-adic field I:Representations of non-integral level

Let F_0 be a non-archimedean local field of odd residual characteristic and let G be the non quasi-split unramified unitary group in four variables defined over F_0. In this paper, we give a classification of the irreducible smooth representations of G of non-integral level using the Hecke algebraic method developed by Howe and Moy.