To detect the cosmic neutrino flux at the highest energies, Askaryan and radar radio detectors are being deployed in the polar regions. The in-ice Askaryan detectors use the radio detection technique to cover multi-gigaton detection volumes to probe neutrino interactions in the polar ice, whereas the in-ice radar technique aims to illuminate a large block of ice with a powerful radio transmitter to reflect radiowaves off particle cascades. It is shown that the neutrino signal is almost perfectly mimicked by cosmic-ray particle cascades moving from air to ice. As such, cosmic-ray showers can serve as essential calibration sources for in-ice radio detectors. However, if not well understood, radio emissions from cosmic ray showers pose an essential background signal in the neutrino search. We present a simulation framework to model the radio emissions from cosmic-ray showers by combining the in-air and in-ice radio emission frameworks to fully characterize the cosmic-ray radio signal as observed by the in-ice antennas.