QAM is a widely used multi-level modulation technique, with a variety of applications in data radio communication systems. Most existing implementations of QAM-based systems use high levels of modulation in order to meet the high data rate constraint of emerging applications. This work presents the architecture of a highly-parallel MPSoC-based QAM modulator that offers multi-rate modulation. The proposed MPSoC architecture is modular and provides flexibility via dynamic reconfiguration of the QAM, offering high data rates (more than 1 Gbps), even at low modulation levels (16-QAM). Furthermore, the proposed QAM implementation integrates a hardware-based resource allocation algorithm for dynamic load balancing.