In a communication system, a mobile terminal compares a first modulationForward Error Correction rate level, which is a modulationFEC rate level used in a previously transmitted signal, with a second modulationFEC rate level, which is a modulationFEC rate level to be used in a currently transmitted signal. In some embodiments, there is a modulator, a transmission chain, a distortion analysis mechanism, and a pre-distortion mechanism, operative to analyze and modify signals so as to counter signal distortion. Thus, the aforementioned moleculers may be more widely used.