In this paper, we investigate the impact of a receiver amplifier on orthogonal frequency division multiplexing (OFDM) and single-carrier block transmission (SCBT) systems which are two potential air interfaces for future short-range wireless communications at 60GHz radio spectrum. We derive a generalized baseband equivalent model for the receiver amplifier by using a power series to capture the nonlinear distortion behavior with several parameters. Based on this model, we develop a simulation flow in the baseband domain for evaluating the system performance deterioration with the non-ideal receiver amplifier. Computer simulations are used to compare the performance of OFDM and SCBT systems under several radio frequency (RF) parameters, such as 1dB compression point, the 3rd-order intercept point, etc. The developed methodology across the baseband and RF can help us jointly optimize the system performance and implementation cost with the nonlinear amplifier at the receiver side.