Cost-effective implementations of wireless transceivers must have a small size and a low power consumption. To this purpose the degree of integration should be increased. This requires new front-end architectures and will result into ICs which combine analog and digital circuits. The development of front-end architectures is best supported by simulations at the architectural level. Current methodologies and corresponding tools suffer from common drawbacks, such as lack of accuracy, long simulation times, etc. A new methodology has been developed for efficient simulation, at the architectural level, of mixed-signal front-ends of digital telecom transceivers. The efficient execution is obtained using a local multirate, multicarrier signal respresentation together with a dataflow simulation scheme that dynamically switches to the most efficient signal processing technique available. The methodology has been implemented in the program FAST (Front-end Architecture Simulator for digital Telecom applications).