A novel reservation TDMA based multiple access scheme using adaptive modulation for multimedia wireless communication systems

This paper proposes an adaptive modulation reservation TDMA system (AM-R-TDMA) for flexible and efficient support of multimedia wireless communication services that require different quality of services under dynamically changing traffic and channel conditions. In the proposed system, a channel for voice and long message terminals is assigned by the reservation TDMA mode, and a channel for short message terminals is assigned by a slotted ALOHA protocol using no signal transmitted period of already occupied channels generated by the voice activation effect. To further increase available slots for short message transmission as well as to increase capacity for data traffic, the proposed system employs an adaptive modulation that controls modulation parameters according to the instantaneous channel conditions. Computer simulation confirms that the proposed system is effective in achieving larger capacity of multimedia communication systems