An enhanced cooperative relay scheme for energy efficiency and capacity improvements in cellular networks

Cooperative technology is deemed to be one of the promising solutions for the next-generation wireless communications. By virtue of the space time coding and diversity combination, an enhanced cooperative relay (ECoR) scheme is designed for the uplink of wireless cellular network, where two users are served by two relay nodes and one base station in a cooperative way. The objective function of the ECoR scheme guides optimisation towards the minimal energy consumption of the whole network under the assumption that the Bit Error Ratio (BER) yielded by the ECoR scheme is lower than the BER yielded by the baseline scheme. The baseline scheme is based on a macro network topology with no relay nodes. The performance of the ECoR scheme is evaluated and analysed by numerical simulations and compared to the baseline, the simple relay (SR) scheme and the cooperative relay (CoR) scheme in terms of capacity and energy efficiency. In the SR scheme a user is served either by a relay node or the base station whilst in the CoR scheme a user is served by the relay node or the base station or both by means of diversity combination. Simulation results show that the ECoR scheme outperforms the baseline, SR and CoR scheme on both capacity and energy efficiency. The gains of capacity and energy efficiency achieved by the ECoR scheme over the baseline reach up to 40% and 107 % respectively.