Inter-Sector Cooperative Relaying for Network Power Minimization

In this paper, we propose to minimize the downlink transmission power through inter-sector cooperative relaying. One common resource block (RB) is shared by two users near the boundary between two neighbouring sectors, and a half-duplex shared relay node (SRN) is introduced along the sector boundary to assist the transmission. The SRN and the two basestation (BS) sectors cooperate to transmit information to the two users. The time sharing factor and frequency sharing factor are jointly optimized to minimize the total network power while satisfying the transmission rate constraint. We also consider rate splitting technique to optimize the cooperation between SRN and BS in order to further reduce the power consumption. Joint optimization is then performed on the message splitting, time and frequency sharing factors. Numerical results show that our proposed scheme can save total network power as high as 10 dB over the system without SRN.