Abstract: A compact superposed modulated signal generator for use in a digital transmission system for transmitting digital information, including a first filter for converting an input NRZ digital data signal into a double interval raised cosine pulse, a second filter for converting the input NRZ digital data into a single interval raised cosine pulse, an attenuator for attenuating the signal output from the second filter, an adder/subtracter for superposing a signal generated by the first filter with a signal controlled by the attenuator, and a third filter for controlling the bandwidth of a signal superposed by the adder/subtracter. The compact superposed modulated signal generator can be used in a satellite communication system, a mobile radio system, and terrestrial microwave communication links.