Method for modulation of carrier signal

plz reply
tell me that if in any kind of modulation the carrier sigal is made up of a large number of frequencies rather than one ,than can u give any idea about the modulated wave

ROADE&SCHWARZ provide modulation simulator soft
Simulation Software WinIQSIM?

http://www.rohde-schwarz.com/www/dev...f/html/1117117

this is a useful tool