Relay selection schemes for the trade-off between cell lifetime and system capacity

Recently, the multi-hop cell networks have been widely studied in order to improve the cell performances and accordingly the relay selection scheme is naturally becoming a key technique to accomplish this advantage. While unfortunately, most of these related works adopted the relay selection scheme neglecting taking the users´ energy consumption into account but partially purchasing the performance improvement such as throughput. To realize the balance between enhancing system capacity and prolonging the cell lifetime, in this paper, the multi-relay AF (Amplify — and — Forward) cooperative transmission technique has been applied to the cell networks and four kinds of relay selection schemes are proposed: maximizing capacity scheme (MCS), energy prior scheme (EPS), mixed energy-capacity scheme (MECS) and weighted energy-capacity scheme (WECS). The simulation results show that by using the potential space diversity, MCS can enhance the system capacity effectively and by using the EPS, the cell lifetime can be better prolonged than the one with no consideration of users´ energy consumption. And the MECS and WECS can both better realize the trade-off between system capacity and the cell lifetime.