R. Frucht and J. Gallian (1988) proved that bipartite prisms of order $2n$ have an $\alpha $-labeling, thus they decompose the complete graph $K_{6nx+1}$ for any positive integer $x$. We use a technique called the $\rho ^{+}$-labeling introduced by S. I. El-Zanati, C. Vanden Eynden, and N. Punnim (2001) to show that also some other families of 3-regular bipartite graphs of order $2n$ called generalized prisms decompose the complete graph $K_{6nx+1}$ for any positive integer $x$.