Changements de base explicites des repr\'esentations supercuspidales de U(1,1)(F)

Let F be a nonarchimedean local field of characterisitic 0 and odd residual characteristic. We describe explicitly the two base change lifts of supercuspidal representations of U(1,1)(F). This represents a step towards the goal of describing base change of endoscopic supercuspidal L-packets of U(2,1)(F).