  We investigate transport and Coulomb drag properties of semiconductor-based
electron-hole bilayer systems. Our calculations are motivated by recent
experiments in undoped electron-hole bilayer structures based on GaAs-AlGaAs
gated double quantum well systems. Our results indicate that the background
charged impurity scattering is the most dominant resistive scattering mechanism
in the high-mobility bilyers. We also find that the drag transresistivity is
significantly enhanced when the electron-hole layer separation is small due to
the exchange induced renormalization of the single layer compressibility.
