Progress in wireless communication enables a person to ring up a friend, send a message, or connect to some website through internet while he is roaming about the world. Although different regions support different communication standards and multimedia services, it is the software defined radio (SDR) framework that ensures enjoyment of such services to a globe-trotter by using only a single handheld wireless device. The work recorded in this thesis aims at designing and developing a common baseband processor which is an important component of an SDR system. Any wireless communication system follows a specific modulation scheme. To support several standards in a single device, realization of more than one modulation schemes is required. Separate hardware implementation of various modulation schemes requires considerable area and power. However, identifying common operators required in the targeted modulation schemes, building optimized units to implement them, and subsequently connecting the modules using a parameter-controlled multiplexing technique leads to a low-area low-power solution.