A multimedia mobile communication system and method capable of updating functions of a multimedia mobile communication terminal is provided, wherein the system and method may add to or modify the functions by modifying a software program. The multimedia mobile communication system and method comprises an intermediate frequency processing unit for correcting an error of an intermediate frequency signal through a convolution coding method or a turbo coding method, downloading a software program and allocating, setting, modifying and upgrading specific functions corresponding to the downloaded software program.