A new resource efficient transmission scheme for cooperative systems

Multiple transmit antennas will play an essential part in order to support a high link quality in wireless communications systems. We employ multiple antennas at the mobile station to perform cooperative space-time coding with other spatially distributed relay stations in a wireless network in order to achieve spatial diversity. Furthermore, through cooperation of the mobile station with relay stations it is possible to cope with distortions due to impairments like, e.g., path-loss and shadowing. Therefore, we propose a regular block Markov superposition encoding strategy based on space-time block codes (STBC) for a cooperative system with one mobile transmitting station and two relay stations, either mobile themselves or fixed. These relay stations cooperate by detecting and retransmitting the information received from the transmitter to the destination. Applying our proposed strategy achieves the same diversity gain of a multiple-input-multiple-output (MIMO) single user system with the same number of transmit and receive antennas. Simulation results show significant improvements in comparison to the system without cooperation.