Integral models in unramified mixed characteristic (0,2) of hermitian orthogonal Shimura varieties of PEL type, Part I

Let $(G,X)$ be a Shimura variety of PEL type such that $G_{{\mathbf{Q}}_2}$ is a split ${\mathbf{G}\mathbf{S}\mathbf{O}}_{2n}$ group with $n\ge 2$. We prove the existence of the integral canonical models of $\mathrm{S}\mathrm{h}(G,X)\mathrm{/}{H}_2$ in unramified mixed characteristic $(0,2)$, where $H_2$ is a hyperspecial subgroup of $G({\bf Q}_2)$.