On the Cooperative and Non-cooperative Relaying in WiMAX Communication Systems

This paper deals with relaying techniques in WiMAX communication system. Different cooperative and non-cooperative schemes are investigated and compared over a complete 802.16 WiMAX-OFDM chain. Realistic channel impulse responses are used. Measurement of some propagation conditions feeds the WINNER channel model in order to generate the channel coefficients belonging to different links. Besides, real characteristics of a relay are taken into account. Simulation results show that the performances of the relaying techniques, at constant relay amplification gain, depend essentially on the propagation conditions pertaining to the different links in the network. They depend also on the received powers from the direct link and the relayed link. Finally, two intuitive power allocation schemes are examined when automatic gain controller is available at the relay.