Multi-code TDMA (MC-TDMA) for multimedia satellite communications

In this paper, we propose a multiple access scheme based on a hybrid combination of TDMA and CDMA, referred to as multi-code TDMA (MC-TDMA). The underlying TDMA frame structure allows for the transmission of variable bit rate (VBR) information, while the CDMA provides inherent statistical multiplexing. The system is studied for a multimedia satellite environment with long-range dependent data traffic, and VBR real-time voice and video traffic. Simulation results show that with MC-TDMA, the data packet delay and the probability of real-time packet loss can be maintained low. The above advantages are achieved at the expense of soft blocking, which occurs when many packets are transmitted simultaneously, but on different spreading codes. Similar conclusions are drawn for simulations where the channel propagation conditions, adjacent beam interference, and imperfect power control are considered