RF front-end architectures of today?s wireless applications need to meet tough requirements on nonlinear distortion to minimize unwanted effects such as crosstalk. An analysis of the nonlinear behavior of analog communication circuits or architectures is not straightforward. This paper presents a modified Volterra series approach to the simulation of nonlinear systems described at the architectural level. The total computed response is decomposed in its nonlinear contributions and the main nonlinearities can be identified. This yields a better insight into the system?s non-linear behavior and allows simplifications. The simplified system can then be simulated more efficiently. The implementation is only based on vector calculation to minimize the computation time, and has been applied to a complete 5 GHz WLAN receiver front-end.