TDMA-based adaptive modulation with dynamic channel assignment (AMDCA) for high capacity multi-media microcellular systems

This paper proposes a time division multiple access (TDMA)-based adaptive modulation scheme with dynamic channel assignment (AMDCA) to realize a high capacity multi-media microcellular system under dynamically changing propagation path and traffic conditions. The proposed method measures the received carrier-to-noise plus interference power ratio (C/(N+I)) of each TDMA slot so as to search available slots as well as to find out the optimum modulation parameters for each slot. As a result, it can effectively combine the mitigating effect of spatially distributed electric field strength by slow adaptive modulation and of spatially and temporally distributed traffic by dynamic channel assignment (DCA). Computer simulation confirms that the proposed AMDCA system can achieve about 3 times higher system capacity than a conventional fixed channel assignment (FCA) using QPSK.