Simulation for a small GSM cellphone repeater

I need help in choosing a simulation package(software) to simulate a GSM phone repeater operating on 1900 MHz or 850 MHz which are the 2 main frequency band used in Canada.

Does anybody knows how to do this or anybody have done this simulation and I need help to first simulate this and then of course impelment the unit. However, at this stage I only need the simulation and the results to have an output of around 1W or less. (the maximum allowed based on government regulations and spectrum canada is 2Watts).

The components and parts I would like to use are Antenna, Duplxere, LNA (low noise amplifiers), and of course the band-pass filter and maybe another stage of power amplifier after the band-pass filter for uplink and the offset frequency for the downlink with the same components for the downstream. I can also send you my overall design on paper and the range of frequency I want to simulate if it will help you more.1850 - 1910 MHz( uplink)
1930 - 1990 MHz (downlink)

thanks a lot