Signal receiver and mobile communication device

For example, it is signal receiving processing equipment for separating a request signal from the analog input signal which is easy to receive the change of signal power from a radio front end. This equipment is equipped with the analog * digital converter for supplying a variable gain amplifier and a digital signal to a digital signal processor, and a digital signal processor contains a digital filter. This equipment is equipped with the control unit which adjusts the filtering accuracy of an analog * digital converter and/or a signal system processor unit depending on the signal quality of an input signal.