Power series and p-adic algebraic closures

In an earlier preprint (math.AG/9810142) we gave an explicit description of the algebraic closure of the field of power series over a field of characteristic p, in terms of "generalized power series". In this paper, we give an analogous description of the algebraic closure of the fraction field of the Witt ring of a field of characteristic p, using an analogue of generalized power series in mixed characteristic due to Poonen.